Objectives : The purpose of this study is to identify the characteristics that affect the urinary phenol of workers exposed to phenol. Subjects and Methods : Total 41 workers were selected at bisphenol A manufacturing plant and their urinary phenol concentration were measured before and after work along with the phenol concentration in the workplace air, and carried out a survey on work characteristics and lifestyle factors that could affect urinary phenol. Results : The phenol concentration in air during work hours was 0.91 (non-detection~2.88) mg/m3, and the worker’s urinary phenol concentrations before and after work were 100.27±75.76 and 138.13±109. 58 mg/g creatinine, respectively, which showed a statistically significant increase. Comparing smoking and urinary phenol concentration, smokers had 194.54±137.52 mg/g creatinine while non-smokers had 108.88±80.10 mg/g creatinine, thus showing the urinary phenol concentration of smokers to be statistically significantly higher (p=0.046). The urinary phenol concentration increased as work hours, the frequency of skin exposure to phenol, and the amount of drinking increased, and there were differences in its concentration depending on the work type and whether or not workers wore protective gear. The results of carrying out a multiple regression analysis showed that phenol concentration in air, work hours, frequency of skin exposure, and smoking were statistically significant. In other words, the urinal phenol concentration increased more for smokers than for non-smokers, when work hours became longer, and when the frequency of skin exposure was over five times. Conclusions : The factors that influenced urinary phenol in workers exposed to phenol were phenol concentration in air, work hour, frequency of skin exposure, smoking, work and lifestyle habits. Accordingly, biological monitoring for phenol exposure assessment must reflect these factors, and effort must be made to reduce skin exposure at workplace. Keywords : phenol in air, urinal phenol, smoking, biological monitoring