Objectives: The purpose of this study was to identify the effect of job characteristics and non-regular work on the toothbrushing habit and oral check-up in Korean worker. Methods: This study was approved for the use of raw data from the 7th Korea National Health and Nutrition Examination Survey (KAHANES, 2016). The raw data was analyzed by complex sampling analysis using IBM SPSS Statistics 21.0 (Chicago, IL, USA). Statistical significance was determined as P<0.05. Results: The non-regular workers had lower rate of toothbrushing more than twice a day, toothbrushing after lunch, and oral check-up than regular workers. Compared to non-regular workers, the odds ratio of toothbrushing and oral check-up at regular workers increased by 1,464 and 1,717 times, respectively. Conclusions: It is necessary to find specific directions to expand the oral check-up program so that all workers, including non-regular workers and part-time workers.