['To explore the effect of cognitive behavioral therapy (CBT) in combination with systemic family therapy (SFT) on mild to moderate postpartum depression and sleep quality.', '249 primiparous women with mild to moderate postpartum depression were recruited and randomly assigned to a control group (n=128), which received conventional postpartum care, or to a psychological intervention group (n=121), which received conventional postpartum care combined with psychological intervention. The Edinburgh Postnatal Depression Scale (EPDS) and Pittsburgh Sleep Quality Index (PSQI) were employed to evaluate depression and sleep quality, respectively.', '104 patients in the intervention group and 109 in the control group completed the study. After intervention, the EPDS score, PSQI score, sleep quality score, sleep latency score, sleep duration score, habitual sleep efficiency score, sleep disturbance score, and daytime dysfunction score were significantly lower in the intervention group than in the control group. The EPDS and PSQI scores of each group at different time points after intervention were markedly decreased compared with those before intervention, and the reduction in the intervention group was more evident than that in the control group.'] Does cognitive behavioral therapy in combination with systemic family therapy improve mild to moderate postpartum depression?