Adolescents face disproportionate risks for negative health consequences related to sexual risk-taking behaviours, including unintended pregnancies and sexually transmitted infections, with Nigerian adolescents showing particularly high prevalence rates despite numerous intervention attempts. This study examined the comparative effectiveness of three therapeutic interventions (Motivational Interviewing, Emotional Mastery, and Cognitive Self-Instruction) on adolescents' sexual risk-taking behaviour and investigated the interaction effect of treatment and socioeconomic status. A quasi-experimental pretest-posttest control group design with a 3×2×2 factorial matrix was employed, involving 180 senior secondary school students from public schools in Oyo State exhibiting high sexual risk-taking behaviours, randomly assigned to three experimental groups (n=60 each), with the Adolescent Sexual Behaviour Inventory (ASBI) as the assessment tool and treatment administered twice weekly for eight weeks. Analysis of Covariance (ANCOVA) revealed significant main effects of treatment on adolescents' sexual risk-taking behaviour (F(2,30) = 6.483, p = 0.025, η² = 0.538), with Motivational Interviewing demonstrating the highest effectiveness (adjusted mean = 149.431), followed by Emotional Mastery (132.681) and Cognitive Self-Instruction (114.263), and a significant interaction effect between treatment and socioeconomic status (F(2,30) = 7.845, p = 0.045, η² = 0.904). All three therapeutic interventions significantly reduced adolescent sexual risk-taking behaviours, with Motivational Interviewing proving most effective, while the strong interaction between treatment type and socioeconomic status highlights the importance of contextualizing interventions within adolescents' broader life circumstances. The study recommends incorporating Motivational Interviewing into sexual health programs, teaching emotional regulation skills, contextualizing interventions to address socioeconomic differences, and training professionals in multiple therapeutic techniques.