Drug information service is one of competencies that pharmacist should have to increase patient compliance on treatment. It needs a good learning method to improve pharmacy student the ability in applying their theoretical knowledge to clinical practice in community later. The study aims to determine effect of problem based learning method on drug information systems course for the ability of drug information service by pharmacy students. The assessment is on aspects of theoretical knowledge, competence of the learning material and case solving abilities. It is a single-blind, case-control study. The study was carried out in19 months, in January 2014 to July 2015 at the Department of Pharmacy, Udayana University. The case group are pharmacy students who receive problem-based learning method, while control group are students who receive conventional teaching methods. A total 79 students are selected, consisting of 38 students in the control group and 41 students in the case group (PBL), respectively. The score of theoretical competence among students in the control group is signifi cantly higher than the case group (p = 0.047). Whereas, the competency of learning material and problem solving ability in the case group are signifi cantly higher than the case group (p = 0.000). The application of problem based learning method can improve the competencies of learning material and problem solving on drug information service by pharmacy students who take drug information systems course. The application of problem based learning method is good to be used at the pharmacy department in general to improve students soft skills, especially in applied subjects relating to clinical practice competencie among pharmacists in the community.