The present works is a descriptive, retrospective and traverse study. This study one carried out in a total of 1196 prescriptions, which fulfilled an inclusion approach and exclusion, in the period of October 2006-February 2007, which were subjected to the evaluation to determine the drug interaction that were presented in the prescriptions, by means of the bibliographical method – analytic. The objectives were to identify and quantify the most common drug interactions in the Gynecology Service, as well as identifying drug interactions greater clinical significance and finally describe the types of drug interactions found in medical prescriptions. The most common drug interactions were: Nifedipine-Magnesium Sulfate (37,31%); Gentamicin-Ketorolac (13,43%) y Ceftriaxone-Amikacin (8,96%), the greater clinical significance accounted for 9% of the total interactions, and interaction Gentami...