The Authors have studied the usefulness and the limits of laparoscopy in the etiologic diagnosis of P.I.D.; for this purpose 21 patients affected with P.I.D. underwent microbiological sampling from cervix and/or vagina and from Fallopian tube during laparoscopy. The findings have shown a discrepancy between the microbiological isolation from vagina/endocervix and from salpinx and remarkably the loss of evidence of S.T.D. agents from tuba with, conversely, frequent isolation of these agents (34.7%) from cervical swabs. Therefore, the Authors believe that the percelioscopic microbiologic study of endosalpinx is essential for the correct etiologic diagnosis of P.I.D., especially in anaerobic germ infections; yet the technical problems of percelioscopic samples and the biological features of S.T.D. agents require the simultaneous bacteriological sampling from the cervix and/or vagina.