This study reports the effect of different levels of wheat/cassava composite flour on liver architecture of wistar rat. The cassava variety- TMS 98/419 and Twenty (20) male wistar rats were used for the study. The ages of the wistar rats ranged between 10-12 weeks and weighed 90-100 g.  After one (1) week period of adaptation, the rats were divided randomly into five groups (A, B, C, D and E) of four (4) rats per group. Group A served as the control while groups B, C, D and E were the experimental groups. The blood glucose levels and body weight of the animals were monitored. The result showed that among the different rat groups, their body weights increased from week 2 of the study while their blood glucose levels significantly decreased (P<0.05) with increase in the quantity of cassava flour. The histo-pathological analysis showed that from 20 % cassava flour substitution, significant distortion of the liver architecture of the wistar rats were observed resulting in intra-hepatic haemorrhage as well as necrosis.  The result revealed that 10 % cassava flour substitution is adequate as this has no effect on the liver architecture of the wistar rat.