Exposure to thioacetamide is associated with the development of liver cirrhosis in experimental animals. In addition to liver, thioacetamide toxicity has been observed in other organs. In this study, the toxic effect of thioacetamide on the spleen was investigated at 0, 4, 8 and 12 weeks post-treatment durations. The level of tissue copper and selenium increased until the eighth week when a significant drop was observed. The zinc level was also increased but returned back to normal by week 8, thereafter it showed further increase. Calculation of the copper/zinc ratio showed an increase, but, recovered and returned to normal value by week 12. The level of manganese fluctuated until the eighth week. It then increased rapidly. Histological studies of the spleen tissue showed a significant increase in extramedullary haematopoiesis in the red pulp region and marked hyperplasia in the marginal zone and follicles. The results of this study, demonstrate an intimate association between trace element levels and spleen pathology, as observed in studies of other organs.