Breast cancer is the most common cancer in women worldwide, with 2.31 million new cases in 2022. The study provides significant insights into the physical, emotional, social and economic challenges these women face in the Mozambican context. The objective of this study is to assess the psychosocial impact and quality of life after mastectomy in women aged between 25 and 65, treated on an outpatient basis at the Oncology Department of Maputo Central Hospital. The study employed an exploratory, descriptive, cross-sectional, and retrospective design, utilizing both qualitative and quantitative approaches. Sampling was non-probabilistic, for convenience. The patients perceived a moderate overall quality of life. The results were obtained using the QLQ C30 and QLQ-BR23 instruments. The QLQ-C30 instrument ranged from 16.7 to 83.3, with a mean of 52.8 (SD = 14.8), significantly lower (p < 0.05) than that considered desirable by European Organization for Research and Treatment of Cancer (M = 61.8; SD = 24.6) and with regard to the QLQ-BR23 instrument, the results of the study showed that “Sexual pleasure” (28.8 ± 34.3), “Future prospects” (17.5 ± 28.0) and “Sexual function” (15.2 ± 21.2) were the functional scales most affected. Patients had a moderate prevalence of depressive symptoms (46.6%). They had high levels of social support (57.1 ± 8.9) and used two coping styles (fighting spirit and anxious worry), being neither fully adapted nor fully maladapted. To improve women's quality of life, special attention should be paid to the domains of women's physical and sexual functioning.