Regional inequalities and centralism are fundamental challenges facing sustainable development planning. This study aims to measure and spatially analyze the development degree of counties in Hamadan province and identify regional disparities within the province. This descriptive-analytical research utilizes the Human Development Index (HDI) model and Geographic Information System (GIS) for data analysis. The investigated indicators were classified into five groups: healthcare, socio-cultural, educational, economic (agricultural-industrial), and physical-infrastructural. Required data were collected from the general population and housing census and statistical yearbooks of 2012. Research findings indicate significant inequalities in development levels among the counties of Hamadan province. According to the results, Hamadan county ranks first with the highest score in the composite human development index and is classified among semi-developed (most privileged) counties. Malayer county is also placed in this category. In contrast, other counties (Asadabad, Bahar, Tuyserkan, Razan, Famenin, Kabudarahang, and Nahavand) are classified as deprived, with Famenin county identified as the most deprived county in the province. The research results reveal the necessity of revising regional policies and balanced allocation of credits and facilities to reduce the development gap and eliminate deprivation in the province's counties, particularly Famenin, Asadabad, and Tuyserkan. Strengthening economic, educational, and healthcare infrastructures in these areas constitutes the main priority recommended by this study.