Context: There is an ongoing debate on the optimal management of patent ductus arteriosus (PDA) in preterm infants. Identifying subgroup of infants who would benefit from pharmacological treatment might help. Objective: To investigate the modulating effect of the differences in methodological quality, the rate of open-label treatment, and patient characteristics on relevant outcome measures in randomized controlled trials (RCTs). Data Sources: Electronic database search between 1950 and May 2020. Study Selection: RCTs that assessed pharmacological treatment compared to placebo/no treatment. Data Extraction: Data is extracted following the PRISMA guidelines. Outcome measures were failure to ductal closure, surgical ligation, incidence of necrotizing enterocolitis, bronchopulmonary dysplasia, sepsis, periventricular leukomalacia, intraventricular hemorrhage (IVH) grade ≥3, retinopathy of prematurity and mortality. Results: Forty-seven studies were eligible. The incidence of IVH grade ≥3 was lower in the treated infants compared to the placebo/no treatment (RR 0.77, 95% CI 0.64–0.94) and in the subgroups of infants with either a gestational age <28 weeks (RR 0.77, 95% CI 0.61–0.98), a birth weight <1,000 g (RR 0.77, 95% CI 0.61–0.97), or if untargeted treatment with indomethacin was started <24 h after birth (RR 0.70, 95% CI 0.54–0.90). Limitations: Statistical heterogeneity caused by missing data and variable definitions of outcome parameters. Conclusions: Although the quality of evidence is low, this meta-analysis suggests that pharmacological treatment of PDA reduces severe IVH in extremely preterm, extremely low birth weight infants or if treatment with indomethacin was started <24 h after birth. No other beneficial effects of pharmacological treatment were found.