The authors made an effort to verify the connection between the presence of risk factors for GDM and results of screening and diagnostic tests. Study group consisted 302 patients. Gestational diabetes was more frequently diagnosed when an excessive maternal weight and family history of diabetes occurred. Among women with gestational diabetes recognised on the basis of the tests results (screening or diagnostic), 1/3 of patients had no evidence of any risk factor. There is no correlation between the number of risk factors and the occurrence of gestational diabetes. The risk factors were present in half of the investigated patients.