AbstractThe growing use of bacteriostats in soaps and the various methods for screening these com‐pounds are reviewed critically. Discussed are (1) in vitro techniques to establish antibacterial activity, substantivity tests using skin disk, fingerprint, or radioactive tracer techniques, and microbiological availability determinations; (2) safety testing procedures; (3) in vivo tests to determine deodorancy and degerming efficiency. Performance in clinical trials, designed to evalu‐ate the contribution of bacteriostatic soaps to the treatment of bacterially caused infections, is ex‐amined. Discussed are studies on the control of erythrasma, acne, diaper rash, and secondary cutaneous infections.These techniques are illustrated by comparing two bacteriostatic systems, A and B, in soaps. System A contains 0.75% TCC and 0.75% hexa‐chlorophene; System B contains 0.67% TBS, 0.67% TCC, and 0.67% Irgasan CF3. The data showed excellent correlation between in vitro screening techniques and actual in vivo per‐formance characteristics.