INTRODUCTION: Scale-up of Option B+ in Zimbabwe has increased antiretroviral therapy (ART) coverage but patient loss-to-follow-up remains high; thus, effective strategies to improve retention in care are needed. Evidence for Elimination, a cluster randomized controlled trial, evaluated the impact of point-of-care (POC) CD4 testing with CD4 count-specific adherence counseling on rates of retention among 1150 HIV-positive pregnant women initiating ART in Zimbabwe. METHODS: Thirty-two primary care health facilities were randomized to offer either standard-of-care (SOC) or POC CD4 testing plus CD4-specific counseling to clients (POC Plus). The primary outcome was the proportion of HIV-positive pregnant women retained on ART after 12 months, calculated by cluster-adjusted proportions, unadjusted and adjusted relative risks (RR and aRR, respectively). RESULTS: Retention in care 12 months after initiation was 50.7% and 54.5% in the POC Plus and SOC arms, respectively (RR 0.93, 95% confidence interval [CI]: 0.78 to 1.11; aRR 0.91, 95% CI: 0.77 to 1.07). Although considered not retained, 9.7% transferred to another facility and 0.2% died. Most women, 95.3% in POC Plus and 92.9% in SOC, initiated ART within 1 month of antenatal booking (RR 1.03, 95% CI: 0.97 to 1.08). DISCUSSION: Although patient retention was similar in both arms, women in the POC Plus arm were more likely to have received a CD4 test at booking and a repeat CD4 test later in care. CD4 is no longer required for treatment initiation but is still recommended in national guidelines and is of value in clinical management. Further work is needed to identify effective strategies to increase patient retention in ART care.