Introduction: A review of the Report on Persons with Disabilities by the Croatian Institute of Public Health identified differences in disability prevalence by county in Croatia. The lowest percentage was observed in Istria (6.4%), whilst the highest in Krapina-Zagorje County (14.4%).Aim: To determine the potential causes of disability prevalence differences between the previously mentioned counties being as they are geographically close.Methods: The literature indicates a statistically significant positive association between various causal factors such as socioeconomic indicators, educational attainment, lifestyle habits and disability. After collecting data on these factors, comparisons were made for the two counties in order to determine the possible causal factors for the disability prevalence difference. Causes and differences in disability prevalence between Croatian counties Krapina-Zagorje and IstriaResults: The results obtained are in accordance with the hypotheses that Istria has significantly better socioeconomic indicators and level of education compared to Krapina-Zagorje County. However, regarding the differences in individual variables such as lifestyle habits, a χ2 test was performed, which showed that there was no statistically significant difference between counties.Conclusion: The results of this study will be used to create policies targeting vulnerable groups.