This paper presents the report of quantitative and qualitative measures of perceived prevalence of academic integrity problems among lecturers of tertiary institutions in Kwara State, Nigeria. Participants comprised 566 students, lecturers and administrative staff selected through the stratified sampling technique from four tertiary institutions; and data were collected via a Questionnaire, Focus Group Discussions and Informal Interview. Descriptive and ANOVA statistics were employed for data analysis across the variables of status, gender and type of institution. Findings of the study showed that relationship with female students, handling of text books/ handouts, project supervision and examinations were perceived by about 10% of the respondents to be the highly prevalent academic integrity problems among lecturers. It was also revealed that only small proportions of lecturers were indicted in this regard. Also, significant differences were found in the perceptions of respondents from the university, college of education and polytechnic. Based on the findings, advocacy was made for implementing laws relating to integrity and instituting academic integrity policy in tertiary institutions in Nigeria.