AIM: Our aim was to assess the prevalence and socioeconomic and clinical correlates of drug-drug interactions among the adult population of transitional Kosovo. METHODS: A cross-sectional study was conducted including a representative sample of 1921 patients aged >/=18 years (mean age: 57.8+/-11.2 years; 50.3% women; overall response: 96%) from the regional hospital of Gjilan, Kosovo, during 2011-2013. Potential drug-drug-interactions were assessed and clinical data as well as demographic and socioeconomic information were collected. Binary logistic regression was used to assess the correlates of drug-drug interactions. RESULTS: Upon multivariable adjustment for all the demographic and socioeconomic factors as well as the clinical characteristics, drug-drug interactions were positively and significantly related to older age (OR=2.1, 95%CI=1.3-2.8), a lower educational attainment (OR=1.4, 95%CI=1.1-1.9), a longer hospitalization period (OR=2.7, 95%CI=2.1-3.6), presence of three groups of diseases [infectious diseases (OR=1.7, 95%CI=1.3-2.4), cardiovascular diseases (OR=1.8, 95%CI=1.4-2.6), respiratory diseases (OR=1.6, 95%CI=1.2-2.5)], presence of comorbid conditions (OR=3.2, 95%CI=2.3-4.4) and an intake of at least four drugs (OR=5.9, 95%CI=4.6-7.1). CONCLUSIONS: Our study provides important evidence on the prevalence and socioeconomic and clinical correlates of drug-drug interactions among the hospitalized patients in the regional hospital of Gjilan, Kosovo. Findings from our study should raise the awareness of decision-makers and policy makers about the prevalence and determinants of drug-drug interactions in the adult population of post-war Kosovo.