The aim of the presented study was to assess the prevalence of type 2 diabetes and prediabetes state in a group of polish patients with diagnosed in 1998-2000 normal glucose tolerance and to assess risk factors determining the development of abnormal glucose metabolism. Participants invited to the study were 1751 people who in 1998-2000 during the„Polish Multicenter Study of Diabetes Epidemiology ”were diagnosed with normal glucose tolerance In all study participants anthropometric measurements, blood pressure, biochemical tests and standardized questionnaire data were examined. Obtained informations were compared with data from the baseline study done in 1998-2000. Using the original criteria (WHO 1999) the prevalence of type 2 diabetes in examined population of 564 people with normal glucose tolerance at baseline, after 8-years of follow-up was 4.43%, IFG was 3.37%, IGT 9.93% and NGT 82.27%. Using the new criteria the incidence rates of diabetes was 4.43%, IFG was 13.48%, IGT was 9.97% and NGT was 72.16% according to the PTD 2011 criteria. In the studied population with normal glucose tolerance according to the WHO 1999 criteria important predictive factors of the development type 2 diabetes were age, 2-h postchallenge plasma glucose, 2-h postchallenge plasma insulin, 2-h postchallenge hiperinsulinemia. In the studied population without abnormal glucose tolerance according to the PTD 2011 criteria important predictive factors of the development of type 2 diabetes were age, 2-h postchallenge plasma glucose, 2-h postchallenge plasma insulin.