OBJECTIVES: This paper constructs a composite index that is sufficiently comprehensive to rank the overall health status of Irish regions and sufficiently detailed to identify the principal sources of varying regional health status. METHODS: We draw on the CSO (Central Statistics Office), PCRS (Primary Care Reimbursement Service) and IPH (Institute of Public Health) health and medicines databases to construct a composite index of the health status of the 8 HSE regions in Ireland in 2010.   Our composite health index (CHI) has 6 component indices. Each maps the regional prevalence of major health conditions for which an ATC (Anatomical Therapeutic Classification) group of drugs was prescribed. Our composite health index, CHI, is a coverage-weighted average of the separate indices we construct for persons covered by each community drug scheme in each region.   RESULTS: Respiratory health status varies most across Irish regions but Cardiovascular, Central Nervous System and ‘Other’ health conditions have higher CHI weights and contribute more to overall regional health disparities.  The Midlands region had the poorest health status in 2010 (8% below the national average); the Eastern region had the best (6% above average), followed closely by the Mid-West. The Mid-West has a better health status than the Midlands despite having lower income and a larger elderly population share. The health status of the Eastern region is just 2% higher than the Mid-West even though its income is 6% higher and the percentage of its population aged over 65 is 1.8 percentage points lower. Simple economic and demographic variables - mean income and the elderly population share – correlate well with health status. CONCLUSIONS: Our index maps significant regional disparities and paves the way for complementary epidemiological studies to trace their underlying lifestyle and medical causes and inform regional health policy.