Background and aims Especially the period between the ages of 0–6, which is known as the early childhood period (preschool period), is a very critical period where learning is fastest, the child is affected the most from environmental factors, and the chance for keeping the acquired attitudes, behaviour and habits in the following years is the highest. As in many subjects, giving the importance to sexual education in this period has many benefits regarding development. This descriptive study was carried out in order to determine knowledge levels and attitudes of doctors and nurses regarding children’s sexual development and sex education.

Methods The design of the study is descriptive. The study was conducted with doctors and nurses who work at various clinics of two state hospitals located in the Istanbul province. A total of 138 doctors and 150 nurses work at these hospitals.

Results It was determined that the majority of cases were female and were aged more than 36 years. 63.5% of the cases have bachelor’s degrees and 62.1% were medical doctors. It was determined that the number of correct responses given by the cases regarding some behaviours observed in children aged between 3–6 years and children’s sexual development and sex education showed significant differences according to age group, marital status, status of having children, educational status, and occupation (Table 1).

Conclusions All of our cases think that it is necessary to provide sex education for children and the majority of cases think that sex education should be provided for children aged between 7–12 years.