Fenarimol, a 2,4'-dichloro-alpha-(pyrimidin-5-yl) benzhydryl alcohol fungicide and steroid demethylation inhibitor, has been reported to affect the actions of multiple CYP450 isoforms, including key enzymes. The aim of this study was to evaluate the effects of fenarimol on a set of biochemical parameters in rats. Rats were intraperitoneally injected with a 200 mg kg(-1) dose of fenarimol. Blood samples were collected for measurements of serum alkaline phosphatase (ALP), alanine amino transferase (ALT), aspartate amino transferase (AST), creatine kinase (CK) activity, and levels of glucose, urea, sodium, and potassium. Serum was analysed at 0, 2, 4, 8, 16, 32, 64 and 72 h following injection. Our results demonstrated a statistically significant increase in ALP; ALT, AST, CK activities and levels of urea from time to time (p<0.05). Our results demonstrate that treatments with fenarimol can alter the activity and levels of selected serum enzymes and biochemical parameters in rats.