| This research transversal, analytical, exploratory and quantitative approach aimed to identify the quality of life of women who have had a mastectomy surgery, relate the results with the strength of the upper limb muscle affected and draw a sociofunctional profile. A total of 10 women participated, from 30 to 60 years old, who underwent to unilateral modified radical mastectomy in a medium-sized hospital in an inner city of Rio Grande do Sul, for at least one year from the date of data collection. The strength of the upper limb muscle was evaluated by manual testing and the handgrip was tested with the dynamometer. A sociofunctional questionnaire was applied and the quality of life data were collected through the European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 questionnaire, followed by the module BR-23. The strength had decreased in all muscle groups homolateral to the surgery. The life quality in a global health bases resulted as regular. The main changes found in the functionality were at scales: emotional, cognitive and sexual. Statistically, it was found significance and correlation between physical health and social function (p=0.04; r=0.65), cognition and functional performance (p=0.01; r=0.75), emotional performance and cognition (p=0.005; r=0.9) and between handgrip of the affected limb with the global health (p=0.008; r=0.77). Breast cancer and mastectomy has a direct impact on the upper limb muscle strength, functionality and on life quality of women, in sexual, cognitive and emotional domains, and physiotherapy plays an important role in the rehabilitation and in social rehabilitation of these. RESUMO | Este estudo transversal, analítico, exploratório e quantitativo teve como objetivo identificar a qualidade de vida (QV) de mulheres mastectomizadas, relacionar os resultados à força muscular do membro superior afetado (MSA) e traçar um perfil sociofuncional. Participaram 10 mulheres, com idade de 30 a 60 anos, que realizaram mastectomia radical modificada unilateral em hospital de médio porte do interior do Rio Grande do Sul havia, no mínimo, um ano contado da data de início da coleta de dados. A força muscular dos membros superiores (MMSS) foi avaliada por meio de testes manuais e a preensão palmar com dinamômetro. Aplicou-se questionário sociofuncional e os dados relativos à QV foram coletados por meio do questionário European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30, módulo BR-23. A força estava diminuída em todos os grupos musculares homolaterais à cirurgia. A QV na saúde global foi percebida como regular. As principais alterações encontradas na funcionalidade foram nas escalas emocional, cognitiva e sexual. Estatisticamente, foi encontrada significância e correlação entre a saúde física e função social (p=0,04; r=0,65), cognição e desempenho funcional (p=0,01; r=0,75), desempenho emocional e cognição (p=0,005; r=0,9) e entre força de preensão palmar do membro afetado com a saúde global (p=0,008; r=0,77). O câncer de mama e a mastectom...