Self-reports of drug use by high-risk offenders interviewed on two occasions were compared to determine the extent to which the reports were consistent at the two interview points. Self-reports of frequency of drug use over the same 12-month period were compared among parolees (N = 380) who had participated in prison drug treatment and who were interviewed at 1 and 5 years following prison release. The kappa coefficient was .31 (p < .001), generally considered a fair level of agreement. Total concordance in retrospective recall of primary drug use frequency was 54.5%.