The study of intestinal antisepsis has been the concern of the author for the past 40 years. Pioneer studies of sulfanilamide, sulfanilylguanidine, succinylsulfanilamide, succinylsulfathiazole, and phthalylsulfathiazole in dogs are reported, and subsequent clinical trials are detailed. By 1948, intestinal antisepsis had become an established procedure to complement adequate mechanical cleansing. Careful attention to meticulous, gentle handling of tissues, preservation of maximum blood supply, and strict aseptic technique should be continued; intestinal antisepsis is not a substitute for surgical principles. A combination of neomycin‐phthalylsulfathiazole, together with the above‐named practices, has resulted in an abdominal wall wound infection rate below 3%, with no intra‐abdominal complications due to postoperative infection.