Summary. The research of rational pharmacotherapy (PhT) in patients with community-acquired pneumonia was performed with application of unified quality evaluation methodology of PhT that had been developed at the Department of Clinical Pharmacy, Pharmacotherapy and Medical Standardization at Danylo Halytsky Lviv National Medical University. The inappropriate (incorrect and irrational) components of PhT were analyzed on the basis of medical prescriptions. Detected remarks were adapted to the European PCNE Classification Scheme V5.01. The results of carried out study allowed to systemize detected remarks and to calculate the expense of irrational PhT according to each group of the remarks.