OBJECTIVES: Comparative estimation cost and influence on quality of life in children with middle severe asthma sodium cromoglycate and sodium nedocromil. METHODS: Cost-utility analysis was conducted in Child's Municipal Asthma-Centre during 1998-2000 years in 100 children with asthma. We determined one year expenses for quality adjusted life years (QALY). For estimation quality of life we used "Childhood questionnaire" by A. West, D. French adapted for Russian by V. Petrov and I. Smolenov and index Rosser-Kind. Estimation of expenditures included direct and indirect expenses. RESULTS: The investigation revealed the differences in therapeutic effectiveness and quality of life depending on treatment method. Using therapy by nedocromil sodium during one year, the total sum of positive effect on quality of children's life was 149,8%; health index 0,985 and expenses on drug - 3672,3±40,4 roubles. Using sodium cromoglycate these indices were 70,9%; 0,965 and 1862,4±24,2 roubles accordingly. Annual cost of middle severe asthma for one child was 5051,4±68,6 roubles using sodium nedocromil (72,7% expenditures formed expenses on the drug); using sodium cromoglycate - 5044,7±110,4 roubles (36,92%) accordingly. In the second case expenses on QALY were much more - 5207,65 in consequence of expenses on hospital care and additional therapy. CONCLUSIONS: Therapy by sodium cromoglycate of middle severe asthma didn't provide complete disease control. In this case necessity in additional therapy for improvement quality of life is increased.