OBJECTIVE: This review was conducted to identify interventions effective in improving uptake and retention of HIV-positive mothers and their infants in prevention of mother to child transmission (PMTCT) services in low-income and middle-income countries (LMICs) in order to inform programme planning. METHODS: We conducted a systematic review of studies comparing usual care with any intervention to improve uptake and retention of HIV-positive pregnant or breastfeeding women and their children from birth to 2 years of age in PMTCT services in LMICs. Twenty-two electronic databases were searched from inception to 15 January 2018, for randomised, quasi-randomised and non-randomised controlled trials, and interrupted time series studies; reference lists of included articles were searched for relevant articles. Risk of bias was assessed using the Cochrane Effective Practice and Organisation of Care group criteria. Random-effects meta-analysis was conducted for studies reporting similar interventions and outcomes. RESULTS: We identified 29 837 articles, of which 18 studies were included in our review. Because of heterogeneity in interventions and outcome measures, only one meta-analysis of two studies and one outcome was conducted; we found a statistically significant increase in antiretroviral therapy (ART) use during pregnancy for integration of HIV and antenatal care relative to standard non-integrated care (pooled AOR=2.69; 95% CI 1.25 to 5.78, p=0.0113). The remaining studies assessing other patient, provider or health system interventions were synthesised narratively, with small effects seen across intervention categories for both maternal and infant PMTCT outcomes based predominately on evidence with moderate to high risk of bias. CONCLUSIONS: Evidence on the effectiveness of interventions to improve uptake and retention of mothers and infants in PMTCT care is lacking. Our findings suggest that integration of HIV and antenatal care may improve ART use during pregnancy. Future studies to replicate promising approaches are needed. Improved reporting of key methodological criteria will facilitate interpretation of findings and improve the utility of evidence to PMTCT programme planners. PROSPERO REGISTRATION NUMBER: CRD42015020829.