The purpose of this study is to examine the mental health level of IT service workers and the mediating effect of depression in the relationship between mental health and oral dryness. For this study, responses to a Google Form survey aimed at IT support personnel were gathered from October 1, 2022 to January 31, 2023. Anxiety, insomnia, somatic symptoms, depression, and oral dryness were investigated as research tools, and a total of 519 people were analyzed using IBM SPSS statistics 27.0 Version. The following are the results: 1) Workers who experienced workplace bullying, conflict, insults, and presenteeism showed negative symptoms of depression, anxiety, insomnia, somatic symptoms, and oral dryness. 2) The more severe the level of anxiety, insomnia, somatic symptoms, and depression, the higher the oral dryness appeared, and a quantitative relationship between variables was observed. 3) Depression showed a partial mediating effect in the relationship between anxiety, insomnia, somatic symptoms, and oral dryness. IT service workers' mental health problems had a direct impact on oral dryness, and as depression symptoms increase, oral dryness also increased more negatively. Depression had a direct and indirect influence on oral dryness. It is necessary to establish a health program to prevent oral health and support mental health of IT service workers and to develop occupational oral health guidelines for workers. This study will be used as basic data for the development of an integrated health management program for IT service workers.