Objective Mastectomy is a highly frequent form of breast cancer treatment in Iran, and sexual dysfunction after mastectomy has been reported in the majority of breast cancer survivors in Iran. In this qualitative study, an attempt was made to examine the stages that patients go through in their sexual lives after mastectomy. Method and materials Using purposeful sampling, 30 married women, who had undergone surgery and had completed an adjuvant treatment period, participated in the study. Data collection was done using in‐depth, open, and semistructured interviews. Content analysis was used. Results Two main categories were identified in the stages the patients go through following mastectomy: sexual function breakdown and restoration of sexual function, each of which involved 3 subcategories, in turn. Subcategories of the first category were perceived physical changes by the survivor and altered sexual behaviors. These 2 factors lead to sexual function breakdown. The third subcategory includes the factors exacerbating the sexual function breakdown. The subcategories of the second category were modification in sexual behaviors, effort for physical restoration, and striving to gain support. Conclusion It was found that in Iranian society, due to cultural context, some taboos, and patriarchal structure, the patients are placed under added pressure following mastectomy. As a consequence, they suffer emotional problems, in addition to physical complications of the disease and its treatments.