This is pilot study to evaluate the relationship of physical fitness with age, body fat, work pattern and life style among 20-9 aged male workers (n=417). Physical fitness was measured by maximum oxygen uptake, forced vital capacity, 1 second forced expiratory volume, grip strength, back strength, sit ups and trunk flexion. Life style was self-reported on a questionnaire about regular exercise, smoking, alcohol consumption, coffee consumption, degree of stress, and percent of body fat measured by bioelectrical impedance fat meter. Age was significantly and negatively related to physical fitness except grip strength. Obesity was next to most significant factor for physical fitness, it was associated with maximum oxygen uptake, grip strength, back strength, trunk flexion. Regular exercise was associated with maximum oxygen uptake. Others was insignificantly related to physical fitness. Performance of physical fitness test was significantly correlated with age, obesity and regular exercise.