Background: Child sexual abuse is a significant public health and child protection concern that can adversely affect the physical, psychological, and social well-being of adolescents. Adequate knowledge about sexual abuse, warning signs, and preventive measures is essential for promoting self-protection and early reporting.

Objective: To evaluate the effectiveness of a nurse-led educational intervention in improving knowledge regarding sexual abuse among adolescent girls and to assess the association between pre-test knowledge and selected sociodemographic variables.

Methods: A quantitative, pre-experimental one-group pre-test–post-test design was adopted among 100 adolescent girls aged 12–15 years at J.S. Inter College, Moradabad, Uttar Pradesh. Participants were selected using non-probability purposive sampling. Data were collected using a sociodemographic proforma and a 30-item structured knowledge questionnaire.

Results: In the pre-test, 72% of participants had inadequate knowledge, while 28% had moderate knowledge; none demonstrated adequate knowledge. Following the intervention, 76% achieved moderate knowledge and 24% achieved adequate knowledge, with no participants remaining in the inadequate category. The mean knowledge score increased from 9.84 ± 3.49 in the pre-test to 18.78 ± 3.65 in the post-test, indicating a mean improvement of 8.94 points (reported p<0.001). Significant associations were reported between pre-test knowledge and age, class of study, father's occupation, family monthly income, and place of residence.

Conclusion: The findings indicate that the nurse-led educational intervention improved knowledge regarding sexual abuse among adolescent girls. Structured school-based educational programmes may contribute to strengthening awareness and preventive knowledge among adolescents.