Decision analysis is a noteworthy methods to solve complex medical problems and select best alternative under uncertainty, and its practical applications in laboratory medicine are anticipated for appropriate usage of laboratory resources. From the view of classical microbiology, it is necessary to identify bacteria causing an infection and select sensitive antibiotics to this pathogen. Decision analysis was used to estimate the clinical and economic implications of microbiological testing for urinary tract infections at the initial visit for all women with acute dysuria. A strategy of initial culture was compared with a strategy involving the use of culture only for patients with symptoms persisting 3 days after initial therapy (wait 3 days strategy). Expected direct cost and medical care days were 10,748 yen and 7.12 days for initial culture strategy and 6872 yen and 7.24 days for wait 3 days strategy. Sensitivity analysis showed that initial culture strategy was not cost effective when the frequency of antibiotics resistant organisms would be increased or required days to obtain microbiological tests results would be decreased.