Prevalence of Sexual Behaviours among Students in Public Day Secondary Schools in Nakuru County, Kenya

Purpose: This study examined the prevalence of sexual behaviours among Form Three students in public day secondary schools in Nakuru County, Kenya, with specific attention to early sexual debut, casual sexual relationships, and cross-generational sexual relationships. Methodology: A correlational research design was adopted. The target population comprised 8,000 Form Three students in 260 public day secondary schools. Multistage, stratified, purposive, and simple random sampling procedures were used to select seven sub-counties, seven schools, and a sample of 367 students. A total of 325 students completed the structured questionnaire, representing an 88.6% response rate. Instrument validity was established through alignment with the study objectives, while test-retest reliability yielded a coefficient of r = .84. Data were analysed using SPSS through frequencies, percentages, means, and correlational procedures. Findings: The findings showed that 59.1% of the respondents had engaged in sexual activity. Among the full sample, 20.3% reported sexual debut before age 15, while 36.6% reported first sexual intercourse between ages 15 and 19. Among sexually active respondents, 35.4% reported two or more sexual partners during the preceding three months, 46.4% did not use a condom during their most recent sexual encounter, and 70.6% reported a sexual partner who was more than ten years older. Unique Contribution to Theory, Practice and Policy: Schools, families, churches, and youth forums should implement regular, age-appropriate psychoeducation and strengthen parental monitoring, nurturance, and open parent-adolescent communication on sexual and reproductive health.