Background <p>Young and middle-aged breast cancer patients suffer not only from physical pain but also from great psychological distress. Therefore, there is an urgent need to understand the factors influencing psychological distress in young and middle-aged breast cancer patients with the aim of reducing such distress.</p> Design <p>Cross-sectional descriptive study.</p> Objective <p>To explore the current status and factors influencing psychological distress in young and middle-aged breast cancer patients.</p> Methods <p>In this cross-sectional survey, relevant evaluations of the research subjects were conducted using a general information questionnaire, the Self-Rating Anxiety Scale, the Self-Rating Depression Scale and the Psychological Stress Thermometer.</p> Results <p>A total of 262 patients completed the survey, and anxiety and depression were positively correlated with psychological distress. Multiple linear regression analysis revealed that anxiety, depression, age, and fertility were factors influencing psychological distress among young and middle-aged breast cancer patients.</p> Conclusions <p>Young and middle-aged breast cancer patients experience a high level of psychological distress. The mental health of these patients should be addressed, and such patients should be provided with timely emotional and psychological counseling to reduce their psychological distress.</p>