This research study of descriptive correlational cross was met with mothers in the maternity service for Trujillo's Hospital Bethlehem, during the months of September to November of 2008, with the purpose of determining the influence of factors biosocioculturales: Age, parity, educational level, origin, occupation, marital status at the level of knowledge of mothers in the maternity service for Trujillo's Hospital Bethlehem. The sample consisted of 208 mothers, who were selected according to criteria of inclusion. Data collection was obtained by the instrument known as: Scale for measuring the level of knowledge about breastfeeding (EMNCSLM), applied through personal interviews, taking into account the principles of anonymity and reliability. The data obtained were tabulated, processed in SPSS version presented in tables 15 and single and double entry, with digital frequencies and percen...