At present there is argument for and against the use of prophylatic antibiotics in simple prolonged ruptured membranes. At Il Sin we studied 96 babies of mothers with prolonged ruptured membranes(58 control, 38 treated). We differentiated between the premature and fullerm babies. The number of premature babies were too small for conparision but in the full term control and prophylactic group, we did not find any difference in complication incidence. The refore, we do not think prophylactic antibiotics are indicated in simple prolonged ruptured membrane of fullterm babies. However further studies are necessary in premature babies.