Objectives: The aim of this study was to identify individuals with undiagnosed diabetes/hypertension and those with known but poorly controlled diabetes/hypertension in a large population-based sample from Dalmatia. We further tried to determine characteristics and traits that were associated with a higher degree of adherence. Materials and Methods: We accessed the data of all subjects recruited in the islands of Vis and Korčula, as well as those from the city of Split. The subjects were classified into four groups: (a) diagnosed, properly treated, (b) diagnosed, improperly treated, (c) incident - newly diagnosed and (d) healthy - undiagnosed. The statistical analysis was based on descriptive and analytic methods. Analysis of variance was used in the numeric data analysis for three cohorts. Chi-square test was used in the analysis of categorical variables. Logistic regression model was used in the final analytic step. All analyses were performed using SPSS v 21 with significance set at P<0.050. Results: We found 14.4% of all subjects to be incident cases for hypertension. Within the diagnosed hypertension group, 60.8% of subjects were improperly treated. 80% of diagnosed diabetes cases were inadequately treated. 10.6% of subjects were found to be incident cases for diabetes. The regression model for prediction of the incident cases of hypertension revealed strong cohort-based differences, with the highest odds in Vis. We further found a strong age-related risk increase, with a significant effect from the years of education – higher education was associated with reduced risk of becoming an incident case. The improperly treated hypertension model indicated even stronger cohort effect, again with Vis as the worst cohort. Regarding diabetes there were no significant differences between Vis and Korčula, while living in Split was associated with a reduced risk to be an incident case (OR: 0.50). Our results suggest that those with lower education and higher socio-economic status were more likely to develop diabetes. Improperly treated diabetes was more likely to be developed by the middle-age group. Conclusion: The probability of having improperly treated hypertension was lower among examinees from Korčula and Split compared to Vis. Our results suggest a positive correlation between incident cases of diabetes and hypertension and living on Vis, older age and less years of education.