A method for the detection of anabolic 17-alpha-alkylated androstane derivatives in both plasma and urine is described and evaluated. The goat and rabbit antisera against 17-alpha-Methyltestosterone-3-carboxymethyloxim-Rinder-serum albumin were raised and compared using [3H]methandrostenolone as a tracer. 22 Steroids including 10 potent synthetic anabolics were tested for their cross-reaction with these antisera.