Objective: This study aimed at identifying a relationship between workers' perceived purpose in life and lifestyle in workers and effective health guidance in occupational health. Method: Using an anonymous self-administered questionnaire, we collected information on demographics, lifestyle, and perceived purpose in life from 638 workers employed at a manufacturing plant. Lifestyle was categorized into good or bad based on the national standards of screening and follow-up. We used the Japanese version of the Purpose in Life (PIL) test, and classified the workers into three groups (low, middle and high purpose in life) with scoring criteria. Multiple logistic regression analysis was used to determine factors associated with purpose in life. Results: The data from 265 of 419 respondents were analyzed. The mean age of respondents was 33.9±8.3 years old, and the age of sex was not significantly. The PIL rates were 50.2% in the low, 36.2% in the middle, and 13.6% in the high groups, respectively. Age and sleep were related to purpose in life, and poor sleep was found to affect purpose in life in the low purpose group (odds ratio 3.213, P<.01). Conclusion: It was identified that the workers who did not get enough rest or sleep had a low purpose in life. These findings suggest that health guidance and education on sleep and rest are needed.