This study was conducted to explore the effects of an event history calendar (EHC) approach on adolescent sexual risk communication and sexual activity. Adolescent school-linked health clinic patients (n = 30) who reported sexual activity self-administered the EHC that was used by nurse practitioners (NPs; n = 2) during a clinic visit. Immediately pre- and post-visit, and at 1 and 3 months, adolescents reported sexual risk behaviors and perceptions about EHC communication on questionnaires and by interview. NPs reported their perceptions of EHCs by questionnaire after the visit and poststudy interview. The EHC approach facilitated communication and adolescent awareness of their risk behaviors. Scores increased on Amount of Communication, t(29) = 8.174, p less than 0.001; Satisfaction with Communication, t(29) = 3.112, p = 0.004; Client Involvement in Decision Making, t(29) = 3.901, p = 0.001, and Client Satisfaction with Interpersonal Style, t(29) = 3.763, p = 0.001. Adolescents reported decreased sexual intercourse at 1 month, p = 0.031. School nurses could use the EHC approach to facilitate adolescent communication and tailoring of interventions. (Contains 1 table and 1 figure.)