The wide spread and distressing heart disease related to smoking resulting from increased level in plasma total cholesterol was the focus of this work. The effect of smoking on serum cholesterol and urea levels of 160 subjects consisting of 80 smokers and 80 nonsmokers (control) was investigated. Total cholesterol and urea levels were determined by enzymatic colorimetric end point (CHOD-PAP) increasing reaction (diagnostic reagent for quantitative invitro determination of cholesterol in serum or plasma on photometric system) and modified Berthelot methods respectively. The mean cholesterol levels were 7.35+0.27mmol/l and 3.34+1.99mmol/l for the smokers and nonsmokers respectively while the mean serum urea level were 9.30+1.14mmol/l and 3.85+0.04mmol/l for the smokers and nonsmokers respectively. There was statistical significant difference in the mean cholesterol and urea levels between smokers and nonsmokers (control) using the student “d”tests. The work showed that the mean serum total cholesterol and urea concentrations were higher for smokers than nonsmokers indicating that smokers are predisposed to cardiovascular disease and possible renal problem.