In women aged under 40 years, breast cancer is the second leading cause of cancer-related mortality. However, research and clinical guidelines are largely based on older populations, resulting in an evidence gap. This article reports the findings of a systematic review of the qualitative literature on the experiences of young women (aged under 40 years) living with breast cancer. Participants in the four reviewed studies experienced substantial physical changes, emotional effects and psychosocial issues; having breast cancer altered their relationships and connections in negative and positive ways; and they adopted various strategies to regain a sense of being in control of their lives. These findings highlight challenges that are unique to young women with breast cancer, such as early menopause, fertility loss and fear of recurrence over a long period of time. In that population group, there is a need for an age-specific approach to care that includes fertility counselling, psychological support and mindfulness-based practices.