Background: Maternal postpartum depression (PPD) is a common problem after childbirth. It is a risk factor for low‑quality mother–infant interaction. Infant massage may help alleviate depressive disorders. Objectives: This study aimed to investigate the effects of infant massage by mothers on maternal PPD. Methods: This clinical trial was conducted on 120 primiparous mothers with PPD. Mothers were randomly recruited and allocated to a control and an intervention group. In the intervention group, mothers were instructed to give their infants 15‑min massage twice daily for 6 consecutive weeks from the 3rd postnatal week onward. However, mothers in the control group did not receive such training. Before and after the intervention, PPD was assessed using the Edinburgh Postnatal Depression Scale. Data analysis was performed using the Chi‑square test, independent‑samples t‑test, paired‑samples t‑test, Wilcoxon signed‑rank test, and univariate and multivariable logistic regression. Results: Groups did not significantly differ from each other concerning parents’ and infants’ demographic characteristics (P > 0.05) and the pretest mean score of PPD (P = 0.46). However, the posttest mean score of depression in the intervention group was significantly lower than the control group (7.75 ± 2.18 vs. 9.2 ± 2.04; P < 0.001). In addition, the posttest relative frequency of PPD was significantly lower in the intervention group (15/60 [25%] vs. 26/60 [43.3%]; χ2 = 4.48; P = 0.034). After controlling the effects of other variables, the odds of PPD in the intervention group was 0.5 times (95% confidence interval: [0.2, 0.94]) less than the control group (P = 0.003). Conclusion: Infant massage by mothers significantly alleviates maternal PPD. Health‑care professionals, particularly midwives, are recommended to instruct mothers to provide infant massage in order to alleviate their own PPD.