As part of the Army's emphasis on performance-based instruction in Basic Combat Training, a study was conducted to provide the Army with data on the retention of skill and knowledge in basic training at Fort Ord, California during March-June, 1974. Selected tests from the Comprehensive Performance Test (CPT) battery were administered to 200 soldiers during their last week of Basic Combat Training (BCT) and were readministered to them six weeks later during their Advanced Individual Training. A single grade of pass or fail was given for each test. The soldiers comprised Mental Categories II-IV, therefore permitting between-group comparisons. The overall results of the study were that depending upon the measure of retention used, there was an average drop of approximately 18% or 26% in performance on the CPT when it was readministered six weeks after the end of BCT. For individual subtests of the CPT, the average decrement in performance ranged between 5% and 44%. Studies employing a longer retention interval and examining the effort necessary for the reinstatement of skills lost or diminished are needed. (HD)