A randomized, controlled, open-label, parallel-group, single-center study to determine biomarkers of exposure to 12 selected harmful and potentially harmful constituents (HPHC) in cigarette smoke, excretion of mutagenic material in urine, and serum Clara cell 16-kDa protein (CC16) in 102 male and female Japanese subjects who smoked Marlboro Ultra Lights Menthol cigarettes (M4JM; 4 mg tar and 0.3 mg nicotine) at baseline. Subjects were randomized to continue smoking M4JM, or switch to smoking either the Electrically Heated Cigarette Smoking System menthol cigarette (EHCSS-K6M; 5 mg tar and 0.3 mg nicotine) or the Lark One menthol cigarette (Lark1M; 1 mg tar and 0.1 mg nicotine), or to no-smoking. The mean decreases from baseline to Day 5/6 were statistically significant (p≤0.05) for exposure to 10 of 12 cigarette smoke HPHC including the primary endpoint (carbon monoxide) and urinary excretion of mutagenic material in the EHCSS-K6M group (-12.3% to -83.4%). Smaller, but statistically significant reductions (p≤0.05) occurred in the Lark1M group (-3.3% to -35.2%), with the exception of urinary mutagens. The largest mean reductions (all p≤0.05) in exposure to cigarette smoke HPHC and excretion of mutagenic material occurred in the no-smoking group (-1.4% to -93.6%). Serum CC16, an indicator of lung epithelial injury, was not significantly different between groups.