The purpose of this study was to investigate the relationship between pack-years of smoking, metabolic biomarkers, and diet quality in male adults. We analyzed data from the combined 2007-2009 Korean National Health and Nutrition Examination Survey (KNHANES). The extent of smoking was quantified in pack-years (py), with 1 py equivalent to 20 cigarettes per day for 1 year. Subjects (n=1,318) were recruited and divided into two groups according to age (30~49 years age group, n=695; ${geq}50$ years age group, n=623). In ach age group, subjects were divided into three groups according to the extent of smoking, which included non-smokers (30~49 years, n=156; ${geq}50$ years, n=217), light smoker (30~49 years, n=269; py<16; ${geq}50$ years, n=189, py<31), and moderate smoker (30~49 years, n=270; $py{geq}16$; ${geq}50$ years, n=217, $py{geq}31$). The Nutrient Adequacy Ratio (NAR) and the number of foods (Dietary Variety Score, DVS) were analyzed by using the data from the 24-recall method. The results showed that moderate smokers were significantly more likely to drink alcohol compared with the other two groups. Triglyceride and cholesterol levels were significantly higher in smoker groups. The non-smoker group consumed significantly higher levels of vitamin C and potassium compared to the smoker groups. In the diet quality, vitamin C NAR of non-smoker group was significantly higher than those of smoker groups. In the ${geq}50$ age group, the MAR of nonsmoker, light, and moderate smoker groups were 0.81, 0.78, and 0.78 respectively. The smoker group consumed significantly greate sugar and oils compared to the non-smoker group. Py showed a significantly positive relationship with serum triglyceride level, and a negative relationship with MAR after adjusting for potential confounding factors. In conclusion, male moderate smokers take too little vitamin C, partly due to low diet quality. Therefore, a well-planed diet must be used to replace the nutrients lost from excluded food groups in smoker.