This study used a survey design to investigate the adoption of software packages in Nigerian university libraries. The study was guided by seven research questions. The population included all the 127 University Librarians in Nigerian university libraries; while the sample used for the study included 58 university librarians cutting across the six geopolitical zones in the country and reflecting the ownership status of federal, state and private universities. An instrument called Software Adoption Questionnaire (SAQ) was developed by the researcher for this study. This SAQ was validated by three librarians from the University of Calabar. The data gathered and collated was analysed using percentages, pie chart and bar chart. The findings of the study indicated the software packages adopted in Nigerian university libraries. The findings also indicated that KOHA is the most widely adopted software package and the most widely used presently; and that the level of automation of university libraries in Nigeria is very low. The findings also indicated the level of automation of the core library modules; how the different levels of automation of the core library modules differ amongst the different modules; how the level of automation of the university libraries in Nigeria differ amongst the private, state and federal universities in Nigeria, amongst others. Recommendations were made to the different stakeholders on the adoption of software packages in libraries in Nigerian universities.