The aim of this study was to provide an integrated evaluation of the effects of chronic exposure to heavy metals in the house sparrow (Passer domesticus) by linking tissue bioaccumulation with hematological, biochemical and reproductive alterations. The study was conducted in two industrial areas of Kosovo (Mitrovica and Drenas) and in one rural reference site. Concentrations of heavy metals (Pb, Cd, Cu, Ni and Zn) were determined in soft and hard tissues using the ICP-OES method. In parallel, hematological parameters (RBC, WBC, hematocrit and hemoglobin) were analyzed, together with plasma enzyme activities (AST, ALT and ALP) and total plasma proteins. Histological analyses of the testes were also performed to evaluate the process of spermatogenesis. The results showed significantly higher concentrations of Pb, Cd and Ni in the tissues of birds from industrial areas compared with the reference site, indicating an increased metal burden in the organism. This increase in tissue concentrations was also reflected in physiological parameters. A decrease in erythrocyte number and hematocrit values was observed, while AST activity was markedly higher in plasma. In some cases, alterations in other biochemical parameters were also detected, indicating the involvement of metabolic processes. Histological analysis revealed structural disturbances in the seminiferous tubules, reduction of germinal layers and decreased spermatogenic elements, suggesting a direct effect on reproductive function. Overall, the findings indicate that heavy metal bioaccumulation in Passer domesticus is associated with simultaneous alterations in multiple biological systems, including the hematological, biochemical and reproductive systems. The integration of these levels of analysis provides a more comprehensive assessment of the biological impact of industrial pollution and highlights the importance of Passer domesticus as a biological indicator for long-term monitoring of heavy metal exposure.