This descriptive study was carried out in order to determine the knowledge levels and attitudes of doctors and nurses regarding children's sexual development and sex education. The study was conducted with doctors and nurses who work at various clinics of two state hospitals located in the province of Istanbul. The data collection tool consisted of 58 questions. The Statistical Program for the Social Sciences, version 18.0 (SPSS 18.0) was used for data analysis. It was determined that females comprised the majority of the respondents (61 %) and were over 36 years of age (54.1 %) (37.81 +/- A 8.82). Of the participants in the study, 63.5 % had bachelor's degrees and 62.1 % were medical doctors. It was determined that the number of correct responses given by the respondents regarding some behaviors observed in children aged between 3 and 6 years and children's sexual development and sex education showed significant differences according to age group (p = 0.007), marital status (p = 0.004), the status of having children (p = 0.004), educational status (p = 0.005) and occupation (p = 0.000). However, in a review of the study findings, it was observed that culture had an important impact on sex-related approaches and that embarrassment and shyness is very common.