Lithium carbonate is commonly used in the treatment of bipolar disorder and in delaying the progression of amyotrophic lateral sclerosis. However a narrow therapeutic window and safety concerns limits its clinical utility. The present study was carried out on forty eight sprague dawley (SD) rats divided in to group I, II, III and IV (each having six male and six female rats) for the period of 30 days to study the effects of lithium carbonate on haemato-biochemical parameters and organ weight. The group I served as control while group II, III and IV were gavaged with lithium carbonate @ 10, 40 and 80 mg/kg bodyweight respectively. Exposures of lithium carbonate resulted in decrease in relative organ weights of spleen, thymus, prostate and uterus and significantly altered the hemato-biochemical parameters as compared to control.