The aim of this study was to identify the determinants of outpatient physician visits and hospitalizations in Bulgaria. In the context of disparities in distribution and scarcity of resources, as well as overutilization of hospital treatment, awareness of possible misuse or underuse of health care services may aid in improving the organisation and managing the costs in the healthcare system. The cross-sectional study analysed primary data from 1292 respondents. Determinants were selected based on the Andersen’s behavioural model. The number of outpatient physician visits (GP, specialist) as well as the number of hospitalizations in the past 12 months were used as outcome measures. Four negative binomial regressions were constructed to assess associations between the independent and the dependent variables. GP visits were positively associated with family size and trust in provider. Older age, higher education, and part-time or unemployed status were associated with lower private visits to specialists. Higher income was associated with fewer visits to the GP and specialist with a referral, while long waiting times, distance and transportation difficulties were positive predictors of more private consultations. Better self-rated health was a negative predictor of GP and specialist visits and the presence of one or more chronic conditions was associated with more outpatient physician visits and more hospital admissions. We have applied the Andersen’s behavioural model, facilitating comparative analyses based on results in different countries and health systems. Identifying the impact of different utilisation rates on population health remains a major challenge.