BACKGROUND: Numerous factors such as nutrition and diet can affect the quality of sleep of people, especially employees. The aim of this study was to investigate the relationship between university employees' sleep quality and their dietary quality scores (HEI, DII and DASH score).MATERIALS AND METHODS: This cross-sectional study was performed on 211 employees with a mean age of 38.75±11.31. Nutritional status of individuals was determined through the Food Frequency Questionnaire (FFQ) and to assess sleep quality, the Pittsburgh Sleep Quality Index (PSQI) was used. The quality of sleep decreases with increasing Pittsburgh index score. The calculated dietary quality scores include DASH Index, Healthy Nutrition Index (HEI) and Diet Inflammation Index (DII).RESULTS: The results of this study after adjusting for confounding showed a significant positive relationship between DASH diet score and sleep duration (p <0.001). There was a significant negative relationship between HEI score and total score of PSQI (P = 0.003). Also, HEI score had a significant positive relationship with sleep duration in the unmodified and modified models (p <0.001), and a significant negative relationship was seen in unadjusted and modified model between DII score and sleep duration (p <0.001).CONCLUSION: It can be concluded that with increasing the diet quality in employees, the sleep quality also increases. This was the first study in south of Iran that examined the quality of sleep and diet of employees and the result of this study can affect the general health and improve the quality of foods consumed by employees.KEYWORDS: Sleep quality, DASH, Healthy Eating Index