Objective: to relate the type of breastfeeding in the women’s sexual function. Method: a cross-sectional study conducted with 150 women in the postpartum period registered in the Family Health Strategy of a large Brazilian municipality. Two instruments were used: one for characterizing sociodemographic, obstetric and breastfeeding variables, and the Female Sexual Function Index for the sexual function. Descriptive data analysis was performed, comparing the variables of interest using the Analysis of Variance, Brown-Forsythe and Tukey tests. Results: there was statistical significance between the groups that practiced different types of breastfeeding in the vaginal lubrication domain (p = 0.015), with the mothers in mixed or partial breastfeeding presenting a higher score for this domain (3.8). Conclusion: there is a difference in the female sexual function between different types of breastfeeding. Women who presented better vaginal lubrication belonged to the mixed breastfeeding group.