BACKGROUND: Previous reports have shown that pulsed dye laser (PDL) is promising for the treatment of acne; however, results provide conflicting evidence. OBJECTIVE: To determine the efficacy of PDL in treating acne vulgaris. METHODS : A systematic review and meta-analysis of studies published before March 31, 2020 was conducted. Randomized controlled trials and case series were analyzed. The meta-analysis estimated the standardized mean difference (SMD) in acne severity score changes in patients treated by PDL versus control and also the SMD of the acne severity scores and comedone counts changes before and after PDL treatment. RESULTS : Eleven studies were included in this systematic review. Six studies were included in the meta-analysis. Pulsed dye laser treatment was not found to be superior to the control group in treating acne vulgaris (SMD: -0.285; 95% confidence interval [CI], -0.886 to 0.317). However, single-arm studies revealed a significantly improved acne severity score after PDL therapy (SMD, -1.321; 95% CI, -2.057 to -0.586), especially when a multiple-session treatment and a longer pulse duration were employed. The comedone counts were significantly decreased after PDL therapy (SMD, -0.596; 95% CI, -1.137 to -0.054). CONCLUSION: When treatment consisted of 4 or more sessions or longer pulse duration, PDL could significantly decrease the acne severity score. [ABSTRACT FROM AUTHOR]