According to the Standard PN-EN ISO/IEC 17025:2000, the laboratory shall confirm that it can properly operate methods before introducing the tests. Enzymatic test, the product of Boehringer Mannheim Co., for determination of sugars in soft drinks was analysed. During the analyses of the method of determination of sugars according to the test standard was tested and statistical analyses were realized. The results of the test show, that the proposed method is suitable for the laboratory environment.