Background: Breastfeeding is the ideal source of nutrition for infants. Breastfeeding can affect sexual activity and sexual quality of women in the postpartum period. Objective: The present study was carried out to determine the effect of breastfeeding on sexual activity and sexual quality in postpartum women. Materials and Methods: The sample of the study consisted of 161 breastfeeding and 176 nonbreastfeeding women who were cared for in the Family Health Centers utilizing the Descriptive Information Form and Sexual Quality of Life-Female (SQOL-F) questionnaire. Results: Half of the breastfeeding and nonbreastfeeding women included in the study had cesarean delivery and the women in both groups reported changes in their sexual life (having less sexual intercourse, and suffering from dyspareunia) during the postpartum period. In the present study, 68.3% of the breastfeeding women and 47.7% of the nonbreastfeeding women experienced dyspareunia, and the difference between them was statistically significant (p < 0.05). There was also a statistical difference between the breastfeeding women and nonbreastfeeding women in terms of the types of changes experienced in sexual life (p < 0.05). The rate of the women who enjoyed sexual satisfaction more was higher in the nonbreastfeeding women (15.9%) than in the breastfeeding women (1.2%). The SQOL-F scale total mean score was 60.07 ± 9.88 in the breastfeeding women and 62.81 ± 9.66 in the nonbreastfeeding women, but the difference between the groups was not statistically significant (p > 0.05). Conclusions: In the present study, the sexual life quality mean scores between the breastfeeding and nonbreastfeeding women were moderate and similar to each other. The fact was that the reported sexual life quality was similar in the breastfeeding and nonbreastfeeding women despite the association of a lower sexual desire and frequency of intercourse in the breastfeeding group, suggesting that breastfeeding may serve as a sexual alternative for nursing mothers.