This study comprehensively assesses weathering and soil development in the alluvial plains of Albania's Drin and Mat rivers. By analyzing soil properties, mineralogical compositions, and weathering indices, it provides crucial insights into the intricate link between geological processes and soil fertility in these key agricultural areas. The focus is on weathering indices such as the Chemical Index of Alteration (CIA), Chemical Index of Weathering (CIW), and Plagioclase Index of Alteration (PIA), which reveal distinct weathering patterns across soil profiles and alluvial plains. Drin River alluvial soils display moderate indices, signaling relatively lower weathering, while Mat River alluvial soils exhibit higher indices, indicating more pronounced weathering. The study emphasizes the role of mineral composition on weathering and soil development, with easily weathered minerals suggesting a more conducive environment for weathering in Mat River soils compared to Drin River soils. Elemental composition differences in these soils significantly impact fertility, potentially affecting agricultural productivity. Correlation analyses highlight the influence of mineralogy and chemical composition on weathering rates. This study's insights into weathering dynamics, mineralogical, and elemental composition in alluvial soils highlight soil fertility implications, crucial for optimizing agriculture and addressing environmental concerns in these vital Albanian regions.