The purpose of this work was to improve the drug dispensing process at the National Institute of Respiratory Diseases of Mexico by applying the six sigma methodology, identifying the non-value added activities as well as the areas of opportunity, in order to make proposals to ensure the supply of prescription drugs to the patient in a timely manner. Seven variables were defined and three indicators were generated, which were implemented in three clinical services of the Institute to measure the current performance of the drug distribution process. With the obtained results, a proposed set of eight improvements were subsequently implemented in a pilot program.