It has been shown that real-life implementation studies for the prevention of type 2 diabetes (DM2) performed in different settings and populations can be effective. However, not enough information is available on factors influencing the reach of DM2 prevention programmes. This study examines the predictors of completing an intervention programme targeted at people at high risk of DM2 in Krakow, Poland as part of the DE-PLAN project. A total of 262 middle-aged people, everyday patients of 9 general practitioners' (GP) practices, at high risk of DM2 (Finnish Diabetes Risk Score (FINDRISK)>14) agreed to participate in the lifestyle intervention to prevent DM2. Intervention consisted of 11 lifestyle counseling sessions, organized physical activity sessions followed by motivational phone calls and letters. Measurements were performed at baseline and 1 year after the initiation of the intervention. Seventy percent of the study participants enrolled completed the core curriculum (n=184), 22% were men. When compared to noncompleters, completers had a healthier baseline diabetes risk profile (P<.05). People who completed the intervention were less frequently employed versus noncompleters (P=.037), less often had hypertension (P=.043), and more frequently consumed vegetables and fruit daily (P=.055). In multiple logistic regression model, employment reduced the likelihood of completing the intervention 2 times (odds ratio [OR] 0.45, 95% confidence interval [CI] 0.25-0.81). Higher glucose 2 hours after glucose load and hypertension were the independent factors decreasing the chance to participate in the intervention (OR 0.79, 95% 0.69-0.92 and OR 0.52, 95% CI 0.27-0.99, respectively). Daily consumption of vegetables and fruits increased the likelihood of completing the intervention (OR 1.86, 95% 1.01-3.41). In conclusion, people with healthier behavior and risk profile are more predisposed to complete diabetes prevention interventions. Male, those who work and those with a worse health profile, are less likely to participate and complete interventions. Targeted strategies are needed in real-life diabetes prevention interventions to improve male participation and to reach those who are working as well as people with a higher risk profile.