Purpose: A food frequency questionnaire (FFQ) and an attitude/behaviour questionnaire (ABQ) were developed, and their validity and reliability were tested to determine adolescents’ vegetable and fruit (VF) intakes and factors influencing their food choices. Methods: High school students living in the lower mainland of British Columbia participated. The FFQ was adapted from the National Cancer Institute VF By-Meal screener, which was designed to be used with adults. After several focus groups with adolescents, the FFQ was revised to make it more user-friendly. The ABQ was developed after a literature review of factors influencing youth VF intake, and was based on the constructs within the Health Belief Model. Results: The FFQ was validated against a written 24-hour dietary record (correlation coefficient = 0.52). The test-retest reliability coefficient for the FFQ was 0.46. A panel of experts tested the ABQ construct validity, and changes were made as a result of the recommendations. Internal consistency reliability and test-retest reliability of the ABQ were 0.71 and 0.59, respectively. Both questionnaires were tested for face validity with students and revised accordingly. Conclusions: Further validation of these two questionnaires against other standardized tools is required. Future studies with adolescents using these tools can guide program and resource development.