Despite the widespread use of cannabis among young people, little research attention has been given to the development of psychometrically sound measures specific to cannabis related problems in this group. The aim of this study was to explore the reliability, validity and factor structure of a multi-dimensional measure of cannabis-related problems among adolescents. The Adolescent Cannabis Problems Questionnaire (CPQ-A) was developed as an assessment tool and treatment outcome measure. A stratified sample of 100 young people (aged 14-18 years) who had used cannabis in the past 90 days were administered the CPQ-A on two occasions 1 week apart. Exploratory factor analysis revealed three factors accounting for 63% of total variance with alpha coefficients of 0.88, 0.72 and 0.73. The CPQ-A was reliable with test-retest correlation for the total CPQ-A being 0.91. CPQ-A score correlated significantly with frequency of cannabis use and number of DSM-IV dependence criteria reported. The findings show promise for the CPQ-A as a reliable, valid and potentially clinically useful measure of cannabis related problems among young people.