Daily VMA variation in urine in relation of fatigue sensation, stress and life stile of nurses on night shift. To evaluate exhaustion objectively in hospital nurses, daily variation of urinaly VMA (vanillyl mandelic acid) excretion was measured in hospital nurses working in daytime and nighttime and it's correlation with the data from Psychological Stress Response Scale (PSRS) test, the burn-out scale, quality and quantity of sleep and daily life stile recorded throughout 24 hours were studied. VMA level in urine showed circadian rhythmic movement, higher in daytime and lower in nighttime. During night shift, VMA in urine in nighttime showed slightly higher level than during day shift but in the subsequent daytime after night shift, VMA level was stillkeeping normal circadian rhythm, resuling flatness of daily fluctuation of VMA level. Dissatisfaction of sleep during daily fluctation of VMA level. Dissatisfaction of sleep during daytime was noticed. Correlation between VMA level in urine and sense of tiredness, stresses or burn-out scale were not carfied in this study because of shortage of samples but working conditions might affect biologicalresponse of exhaustion.