Prevalence of pneumonia Yogyakarta increased from 1,8% in 2013 to 4,3% in 2015. The treatment for pneumonia which caused by bacteria is using antibiotic. Many cases were found irrational antibiotic using, which can cause antibiotic resistance. This study was aimed to evaluate the use of antibiotic at Rumah Sakit Khusus Paru Respirat Yogyakarta in 2015. This sudy was a non-experimental design with descriptive analysis. A secondary data was collected with retrospective study from the medical record of pneumonia patientat Rumah Sakit Khusus Paru Respira Yogyakarta in 2015. Sample was total 83 samples. Evaluation of antibiotic use was assessed qualitative based on the Gyssens criteria. The results showed that the most of antibiotic therapy used is for pneumonia patient was ceftazidime 44,44%, consist of 51 antibiotics (80,95%) for monotheraphy, 12 anibiotics (27,59%) for combine theraphy and 2 antibiotics (3,45%) for replacement therapy. The result of Gyssens assement among 58 patients showed that 18,97% not sufficient medical record, 1,72% there is a more effective antibiotic, 1,72% the admistration of antibiotic is too long, 1,72% inappropiate doses, 75,86% rational of antibiotic.