This article presents for the first time all of the technical details of the authors'' chick comb method for androgen assay. It includes prep. of material for assay, conditions and technique of the procedure, and the method of calculating the final result. The latter is presented in such a way that the calculations can be performed either by direct application of the dose-response equation previously reported (involving the weight of comb, initial and final body weights; and the number of chicks of each sex) or by the use of a chart which employs only simple arithmetical procedures. This chart is presented together with an illustrative example. For uniform comparison of data, it is stressed that all the details of technique be followed without variation.