OBJECTIVES: This study was performed to evaluate the sleep patterns in a population of Korean labor workers and to assess the activity of the autonomic nervous system in relation to sleep habits. METHODS: A sampler of 1238 daytime workers (male 911, female 327) completed questionnaires on sleep habits and their short term heart rate variability(HRV) was also examined. We used the SA-2000 (medi-core) instrument for 5 minutes for each participant in the morning and performed basic physical examinations including height, weight, and blood pressure. RESULTS: Bed time and wake up time were negatively correlated with age, while the frequencies of waking up through the night and in the early morning showed positive correlation with age. We found that bed time and wake up time during weekdays, sleep latency during weekdays, frequency of waking up through the night, and the degree of sleepiness all varied significantly according to the average nightly amount of sleep within the last week. There was a positive correlation between wake up time at weekdays with mean heart rate. However, the other variables of sleep habits and pattern did not show significant correlation with HRV. CONCLUSION: Among Korean daytime workers, sleep phases become advanced with aging. In spite of the aging processes, general sleep health seems to be maintained among the healthy worker group. However, short-term HRV was not useful parameter to measure the alternation of autonomic nervous system resulting from the difference of sleep habits and pattern.