Sample attrition, a major concern in any longitudinal study, is even more problematic when adolescents are the study population. The need to minimize the loss of participants in order to maintain the integrity of the cohort is vital in substance abuse prevention evaluations. The Adolescent Substance Abuse Prevention Study (ASAPS), a national school based prevention study being conducted in six sites across the country, followed students attending schools randomly assigned to either a treatment or control condition from the seventh through the eleventh grade. The percent of study dropouts after the ninth grade pretest warranted consideration of an attrition study to acquire data from those students who were no longer in a study school. A pilot study conducted with a sample of attrition cases in one site (51 of 495) was undertaken to assess the feasibility and costs of a full study. This paper describes the experiences gained from this pilot study in tracking study subjects. An exhaustive protocol was developed and contacts with parents were initiated through telephone calls and flyers sent by mail. Online public records and telephone directories were used to acquire additional contact information. Contact was established with 56.8% of the parents and resulted in completed surveys from 19.6% of the sample at a cost of $1,949.30 per survey.