A drug use inventory and a drug attitude scale were examined for validity, while a drug knowledge test was examined for content validity. To test reliability, each measurement tool was subjected to item analysis for internal consistency. Investigators obtained necessary data from 150 inmates at two county correctional institutions. Factors considered during instrumentation included subjects' reading and comprehension levels, drug experiences, and willingness to participate in data collection. Also discussed are implications and suggestions concerning the use of such instruments in inmate drug education. Tables and 16 references are supplied. (Author abstract modified)