Breast cancer is prevalent in females, accounting for 25% of the world's cancers. Prevention is strategic, and the nurse is an active part in educational and preventive programs, highlighting how the need for preventive nature is combined with gender medicine. The objective was to investigate the knowledge of breast cancer prevention among inmates of Bollate prison (Milan). 51% (52) adhered; women had an average age of 44 years (SD: 9.8), and 39% (20) were inmates from 1 to 3 years. 93% (48) knew about breast cancer prevention, 43% (26) had undergone specific preventive checkups outside of the prison, and 62% (31) had performed self-palpation. All women felt it was important to implement prevention in the prison environment. A high percentage of female inmates with an educational qualification was observed to be aware of breast cancer prevention and to have undergone screening programs in their lifetime. Emerges the strong willingness of women prisoners to be involved and the educational role of the nurse in the prison setting also from a gender perspective.