Diabetes mellitus is a group of metabolic diseases that occur due to the lack of insulin secretion, insulin work disorders, or both. Pharmacists have an obligation to help a patient to increase the effect of drug therapy , so that required to lead the good ability and knowledge about pharmaceutical skill ( skill lab) for the use of a drug diabetes mellitus especially insulin. The aim of this study is to know the influence of pharmaceutical skills on knowledge of pharmacy students of Universitas Muhammadiyah Yogyakarta (UMY) about the use of insulin. This study used quantitative correlation method with cross sectional approach. The pharmaceutical skill and knowledge about the use of insulin on pharmacy students of UMY were considered from the spread of questionnaire to the 120 students of 2013 and 2014 containing 7 questions about pharmaceutical skill and 17 questions about knowledge of insulin usage, that has been tested of validity and reliability before by handing out questionnaire to the 20 respondents. The results of the validity showed that all the statements were valid with r count was positive and r count > r table. The reliability test expressed reliable because alfa cronbach was larger than 0.7, which was 0.923. The result of this study showed that there was a positive influence of pharmaceutical skill on the knowledge of pharmacy students of UMY about the use of insulin as much as 15,2% for the students of 2013 and 11,1 % for the students of 2014.