BACKGROUND: Obsessive-compulsive disorder (OCD) is often comorbid with Bipolar Disorder (BD), complicating its presentation and management. OCD prevalence rates in BD vary widely across studies and recent meta-analyses.OBJECTIVE: We performed a comprehensive systematic review and meta-analysis of studies reporting cross-sectional or lifetime OCD prevalence in BD, assessed by meta-regression various determinants of estimated prevalence and compared it with major depressive disorder (MDD) patients and general population subjects included in extracted studies.METHODS: Relevant articles published up to January 2019 in PubMed/MEDLINE were retrieved. Prevalence rates underwent Freeman-Tukey double arcsine transformation before meta-analysis.RESULTS: We included 29 studies reporting cross-sectional prevalence (N = 6109) and 39 studies reporting lifetime prevalence (N = 8205); eight studies reported both. The pooled lifetime and cross-sectional prevalence of comorbid OCD in BD was estimated at 10.9% (95% CI: 7.8-14.4%) and 11.2% (7.6-15.3%), respectively, in the random-effects model. Respective estimates in the general population were 2.5% and 1.6%. Study setting (epidemiological or clinical), diagnostic criteria and procedures, gender, BD subtype and remission status could not explain heterogeneity of prevalence estimates in meta-regressions. Age had a small yet significant negative correlation with lifetime prevalence. OCD prevalence in BD was not significantly different than in MDD.LIMITATIONS: Search was limited to English-language literature.CONCLUSIONS: Lifetime OCD prevalence in BD was 4.4 times higher than in the general population. Cross-sectional prevalence was as high as lifetime, suggesting that OCD in BD is more chronic/ persistent than in the general population, where cross-sectional stands at about two thirds the lifetime prevalence.