The present investigation aimed at evaluating blood chemistry and histological changes in liver of male rats exposed to mercury (20 ppm) in their drinking water for 8 weeks. Body weight was recorded at weekly interval during the exposure period and after 8 weeks, blood was collected for serum analysis and thereafter the animals were sacrificed by cervical dislocation and their liver was collected for histopathological studies. For light microscopy the liver tissue was stained with haematoxylin and eosin. The body weight gain in the mercury exposed animals lagged behind the controls. Almost all blood parameters analyzed in the present study were altered significantly in the mercury exposed animals as compared to the control. The liver tissue was conspicuously damaged and degenerative and necrotic changes were observed in almost every areas of the mercury exposed liver tissue. The blood parameters studied herein may serve as potential serum enzyme biomarkers for mercury-induced hepatotoxicosis which ultimately affects the general health of the animals by inducing alterations in the integrity of the vital organ liver.