In Cameroon, patients with breast cancer are more often diagnosed at stage III and IV, hence the need of preventives actions. Knowledge and attitude of medical personnel may influence their practice with regards to screening and early detection of breast cancer. Very few is known about this subject in Cameroon. The objective was to describe the knowledge, attitude, and practice of health care professionals on breast cancer risk factors, diagnostic methods, and screening. This was a cross-sectional study conducted during a 6-month period, among health professionals of Douala General Hospital and Laquintinie Hospital, Cameroon.Data were collected using a self-administered questionnaire which included demographic characteristics, questions on breast cancer risk factors, screening, and diagnostic methods. Marks were attributed to each question and calculated for each section. Participants fell in four categories of knowledge, attitude, and practice: very weak, weak, good, and excellent. The software XLStat7.5.2 was used for data analysis. Overall, 445 health professionals were interviewed. The average age was 39 ± 9 years. The level of knowledge, attitude, and practice was accessed respectively as weak (50.1%), very good (64.5%), and poor (36.4%). The personal practice of female workers was poor (43.0%). Compared to participants with very weak to weak knowledge, those with good to excellent knowledge had 1.55-fold odds of excellent attitude p < 0.0001. After multivariate analysis, the factor associated with good to excellent knowledge was the participant qualification (academic degree). These results suggest the need for training of health professionals in Douala references hospitals on breast cancer risks factors, diagnostic, and screening methods.