The authors give general considerations about the employment of tetracycline compounds in infectious diseases. They describe their experience in the application of tetracycline laurilsulfate in intramuscular infections. They dealt with 19 different kinds of infections with this drug: 5 acute pharyngitis, 8 pulmonary infections, 2 acute enteritis, 1 furunculosis, 1 pyelonephritis, 1 erysipelas, and 1 panaris. They got 15 excellent, and one good results (84,2%). Collateral phenomenons were not observed by them, excepting one case of urticaria.