Child sexual abuse, also called child molestation, is a forms of child abuse in which an adult or older adolescent uses a child for sexual stimulation. Childhood Sexual Abuse (CSA) is a major concern that causes greater psycho-social impact on the children. This study aims to develop and evaluate the effectiveness of educational programme regarding prevention of child sexual abuse on level of knowledge among mothers. Objectives: to assess the pre-test level of knowledge regarding prevention of child sexual abuse among mothers, and to determine the effectiveness of educational programme on the level of knowledge regarding prevention of child sexual abuse among mothers, to find out the association between the pre-test score on level of knowledge on prevention of child sexual abuse with the selected socio demographic variables of the mothers. Method: The study has adopted quantitative research approach and pre-experimental design (one group pre-test and post-test design). Total 10 mothers were selected based on inclusion and exclusion criteria through non convenience sampling technique. Data was collected in terms of socio demographic profile of the mothers, self-administered knowledge questionnaire regarding prevention of child sexual abuse. Results: Findings of study showed that 50% mothers in pre test were having poor knowledge and 50% were having average knowledge. The majority of mothers in post test were having good knowledge i.e. 80% and 20% had average knowledge . There is no significance association between the level of knowledge scores and socio demographic variables. The result from this study reveals that knowledge regarding prevention of child sexual abuse among mothers were inadequate. Also, the educational programme significantly improved the knowledge of mothers regarding child sexual abuse so other teaching strategies can be used to increase mother’s knowledge regarding prevention of child sexual abuse.