Approximately a third of newly diagnosed invasive breast cancers occur in women aged under 50 years and it is likely that the incidence of the disease in younger women will further increase as a result of demographic and lifestyle changes and progress in screening. Breast cancer in young women is different from that in older patients. Young women with breast cancer represent a distinct population for which tailored diagnostic, therapeutic and supportive interventions are required. This review highlights the complex diagnostic and therapeutic processes that women and care providers are faced with. Topics addressed include the need for more sensitive and specific diagnostic tools that are capable of detecting cancer in dense breasts, the development of individualized surgical and medical treatments in the early and advanced disease setting aimed at improving outcome and reducing long-term side effects, and adequate psychosocial interventions.