The policy framework guiding Kenya's response to the AIDS epidemic identifies voluntary counseling and testing as crucial to risk reduction and HIV‐preventive activities. Yet in Kenya, as in most sub‐Saharan countries, voluntary testing rates are low, especially among young people. Using hierarchical linear models, we identify both individual‐ and teacher/school‐level factors that affect voluntary HIV testing among secondary school students in Kenya. Results indicate that adolescents are more likely to test for HIV serostatus when they are knowledgeable about testing, have been involved in HIV/AIDS activities in primary school, have been provided with HIV information in secondary school, perceive themselves as at high risk of contracting HIV or know of someone infected with or who has died from HIV/AIDS, and have ever engaged in sexual intercourse. Barriers include fear of going to testing centers and being perceived as HIV‐positive. Teacher/school‐level characteristics are relevant for explaining rates of HIV testing, especially among girls. To encourage testing, policymakers should attend to teacher/school‐level factors as well as individual characteristics of students.