Introduction: As it may not be feasible to provide cervical cancer screening services to all HIV-infected women in most resource-limited settings, there is a need to identify those who are most at risk. We determined the prevalence, patterns, and associated factors of cervical cytological abnormalities among HIV-infected women in Lagos, Nigeria. Methods: This descriptive cross-sectional study was conducted among HIV-infected women at the adult HIV treatment and colposcopy clinics of a university teaching hospital in Lagos, Nigeria, between October 2018 and December 2019. A cervical sample was collected from each woman to detect cervical cytological abnormalities. Results: Of the 593 enrolled women, cervical cytological abnormalities were present in 40 (6.7%). Most (37.5%) of the women with cytological abnormalities had atypical squamous cells of undetermined significance. Age at coitarche (<20 vs. ≥20 years: adjusted odds ratio, 2.42; 95% confidence interval, 1.21–4.83, p = 0.01) was the only factor that was independently associated with cervical epithelial abnormalities. Conclusion: The prevalence of cervical cytological abnormalities in our study is lower than most previous reports in Africa. Sexual debut at an early age was significantly associated with cytological abnormalities. It is necessary to confirm the findings of this study through a well-designed and adequately powered longitudinal study.