An imbalance between oxidative stress and antioxidant capacity has been proposed to play an important role in the development and progression of chronic diseases in the elderly. The present study was carried out to investigate correlation between the serum antioxidants (lycopene and alpha-tocopherol) and malondialdehyde (MDA), a marker of oxidative stress in the healthy Thai elderly. The 207 healthy subjects aged 60-91 years old (72 males and 135 females) in Khon Kaen province, Thailand were enrolled in this study. They were interviewed by questionnaires about smoking habit. Serum lycopene and alpha-tocopherol levels were determined by high performance liquid chromatography (HPLC). MDA was measured by thiobarbituric assay. Serum lycopene and alpha-tocopherol levels in the elderly were 0.27 micromol/L (95% CI = 0.23-0.31) and 22.10 micromol/L (95% CI = 20.99-23.22), respectively. Males had significant lower serum lycopene and alpha-tocopherol levels than females (p<0.001). Of 72 males, 31.94% are current smokers whereas 1.4% of 135 females are current smokers. Current smokers had significantly lower serum lycopene (0.17 +/- 0.11 micromol/L) than current non-smokers (0.28 +/- 0.27 micromol/L) (p=0.0439) but level of alpha-tocopherol had non significance (p=0.210). Moreover, the current smokers had higher MDA malondialdehyde level (1.55 +/- 0.10 micromol/L) than the current non-smokers (1.35 +/- 0.04 micromol/L) (p=0.094). Thus, dietary antioxidant supplementation from local fruits and vegetables may have a beneficial role in the prevention of chronic diseases at high-risk oxidative stress such as smoking in these elderly.