Several factors are associated with sexual satisfaction during the postpartum period. However, there is a lack of studies among low-income women with depression during the previous pregnancy. The aim of the present study was to estimate the prevalence of Decline of Sexual Life (DSL) and its relationship with postpartum depression (PPD), at 6 to 9 months after childbirth, in a primary care sample of mothers who had antenatal depression. We performed a cross-sectional, secondary analysis from a cluster, with 356 postpartum women from public primary care clinics in São Paulo, Brazil. The main outcome measure was the women's perception of DSL after pregnancy/delivery. The main exposure variable was PPD assessed with the Patient Health Questionnaire. A questionnaire evaluated self-perception of partner relationship and obstetric and socio-demographic maternal characteristics. Crude and adjusted Prevalence Ratios, with 95% confidence intervals, were calculated using Poisson regression. DSL occurred in 25.0% of postpartum women. In the multivariable analysis, PPD was associated with DSL and self-perception of partner relationship. In conclusion, DSL is common among postpartum women with a history of antenatal depression. The screening of sexual problems after childbirth should include assessment of PPD and perception of partner relationship, both variables amenable to interventions.