Catha edulis (miraa) is a large green shrub that grows at high altitudes. It is a well-known tree in Kenya.The leaves of the C.edulis plant contain alkaloids structurally related to amphetamine and they are currently chewed daily by a high proportion of the adult population in Kenya for the resulting pleasant mild stimulant action.The habit of C.edulis chewing is widespread in Kenya especially in C.edulis producing areas and this poses a public health problem.This study was conducted tocompare the effects of red and pale green variety of Catha edulis on human consumers in Meru County. Blood was collected from 198 Catha edulis chewers and 193 non-chewers.Liver biochemical parameters were affected by the red variety Catha edulis chewing which was shown by increased activity of alanine aminotransferase (ALA), total bilirubin (TB) and alkaline phosphatase (ALP) as compared to the pale green variety. Renal biochemical parameters were not affected. In conclusion, red variety Catha edulis is more potent than the pale green variety hence responsible for hepatic toxicity but not renal toxicity.