Imo State University was established on 23 February 1981 through the passage of Law No.4 by the Imo State House of Assembly in Owerri the State capital. The law establishing the university was amended by Edict 27 of 1985, another edict in 1988 and by the passage of Law No.2 of 1992 relocating the university to its present site in Owerri. The university commenced academic activities at a temporary site located at the former Madonna High School, Ihitte. The decision to establish a State university arose when the absence of a federal university was greatly felt by the people of Imo State whose major industry is education. The State had so many qualified candidates who could not be admitted into the existing universities.

The Government of Imo State under Chief Sam Mbakwe established the Imo State University as a response to the yearnings of the people after completing due processes of approval from the Federal Government. The decision to establish the university was also informed by: the need to provide a relatively easy and effective mechanism for producing various cadres of manpower for the State; and the anxiety of both the Government and people of Imo State to join the select group of regions of Nigeria that could boast of having their 'own' university.

Imo State University was established as a liberal studies tertiary institution. The University was designed as a multi-campus structure with each college to be located in the Senatorial Zones of the then Imo State. Thus, the main campus was located at Etiti in the Okigwe Senatorial Zone while the Aba Campus in Aba Zone, housed the Colleges of Business and Legal Studies. The first set of about400 students came into residence on 23 October 1981 and matriculated on 19th day of December of the same year.

Subsequently the multi-campus structure was phased out, because of a serious problem of inadequate space. Thus, the University was in 1986 relocated to a consolidated campus at Uturu (Okigwe). With the creation of Abia State in 1991 out of the former Imo State, the entire physical facilities and human resources of Imo State University were ceded to Abia State as the land housing the University belonged to the Uturu community in Isiukwuato Local Government and thus became the property of Abia State.

Consequently, the Imo State Government of Chief Evans Enwerem in April 1992 re- established the Imo State University in Owerri. Two options were considered by the Imo State Government in the re-establishment of the university at Owerri. The first option was to move at once, all the staff and students at the various stages of their programs in Uturu who wanted to remain in newly re-established Imo State University presently at Owerri. The second option was to rebuild the university at Owerri over a specified period of time. The second option was adopted after various consultations by government and a target period of 5 years within which to complete the re-establishment of the university at Owerri was considered. Professor T.O.C. Ndubuizu, Deputy Vice-Chancellor, University of Nigeria, Nsukka was then appointed the Vice-Chancellor with the onerous responsibility of relocating and re-establishing Imo state University at Owerri.

At Owerri, the Imo State University was temporarily accommodated within the campus of Alvan Ikoku College of Education from May to December 1992. The University later moved to its own premises of four buildings within the Federal University of Technology, Owerri, at the Lake Nwaebere Campus. With the translocation of the Federal University, Owerri to its permanent site at Ihiagwa near Owerri, the Lake Nwaebere Campus of that University was then acquired for Imo State University Owerri. The first batch of students was allocated to the new Imo State University by the Joint Admissions and Matriculation Board (JAMB) in February 1993. The National Universities Commission also formally approved the reestablishment of the university in 1992 at the Lake Nwaebere Campus.

The academic programs of Imo State University were initially organized in colleges and schools. However, the unwieldy collegiate system was replaced by the new faculty structure at the beginning of the 2001/2002 academic session. This is in line with the law establishing the Imo State University. The transition gave rise to some faculties and many departments, with only the College of Medicine and Health Sciences retaining its original status. The University offered undergraduate, postgraduate and diploma programs in various disciplines. In addition to its regular full-time and part-time programs, the University catered for the educational needs of the various segments of the Nigerian public through its sandwich programs, Institute of Continuing Education Program (ICEP) and Outreach and Consultancy Services (OCS) programs.

The take-off students' population of the university was 420 in the 1992/93 session. The students' population has grown steadily and the number of students under taking various diploma and degree programs of the university through its Full-time, part-time, sandwich, ICEP and outreach programs grew to about 24,000 with an academic staff population of about 1,131 by 2007.

The University graduated its first batch of students in the 1996/97 session. In April2002, the 4th Convocation ceremony of the relocated and now re-invigorated Imo State University took place during which 2,309 and 871 graduates were awarded various first degrees and postgraduate diplomas/degrees respectively.

The Imo State University is now one of the best universities in Nigeria with highly qualitative academic programs for the training and character formation of tomorrow's leaders. The result of the 1999/2000 accreditation exercise of the National Universities Commission confirmed the high rating and acceptance of the university by the Nigerian public. The university was ranked 1st among all State universities in Nigeria and the 10th overall among both State and Federal universities.

The law establishing the Imo State University was amended by Law NO.5 of 2004 signed into law by the Executive Governor of Imo State, Chief Achike Udenwa on 2nd November 2004. The new law provides for the restructuring of Imo State University Owerri. The law is cited as the Imo State University Owerri Law 2004.

The motto of Imo State University is 'Excellence in Service'. The motto provides the inspiration, motivation and guiding principle for staff and students of the University to excel in teaching, learning, research, and community service. The motto also provides a linkage between services offered by the university and the host of stakeholders serviced by it.