Objective: the objective of the study is to assess the patterns and predictors of contraceptive usage among HIV positive women of reproductive age attending PMTCT/ART clinics in Ogbomoso, Oyo state, Nigeria. Methods: it was a cross-sectional descriptive cross-sectional study conducted among HIV positive women of reproductive age group selected using multi-stage sampling technique. Data was collected using a pre-tested semi-structured interviewer administered questionnaire and analyzed using Statistical Package for Social Sciences. The questions about knowledge of and attitude towards contraception were scored, and categorized as good or poor knowledge, favourable or unfavourable attitude. Univariate, bivariate, and multivariate analyses assessed predictors of contraceptive usage. A bivariate logistic regression model which used p<0.05 as the entry criterion, was generated to calculate the odds ratios and 95% confidence intervals respectively. Results: age ranges from 16 to 48 years with mean age 31.8 + 7.8 years. Majority are within age range of 25-35 years 110 (40.7%), Christians 178 (65.9%), Yoruba 235 (87%), educated 246 (91.1%) and within monogamous settings 179 (66.3%). About half of the respondents 158 (58.5%) had favorable attitude and adequate knowledge respectively. There is a significant difference (p<0.05) between education and categorized knowledge on usage of contraception. Those who have adequate knowledge are twice more likely to use contraception compared to those with inadequate knowledge. Those who are less educated are 3.3 times less likely to use contraception compared to those that are educated. Conclusion: The findings in this study showed that about half of the respondents had high knowledge and favorable attitude on family planning.