Background and Objectives: Mental workload and chronic fatigue in the workplace are challenges that affect employees' capabilities
and health. The aim of this study is to examine the correlation between the subscales of mental workload and various physical and mental dimensions of chronic fatigue in small industries and related jobs.

Methods: This descriptive-analytical cross-sectional study was conducted on employees of small industries in Eghlid with a sample size of 247 participants. Data were collected using three questionnaires: demographic information, NASA-TLX, and Chronic Fatigue Scale (Chalder). For data analysis, Spearman's correlation test and SPSS software were used.

Results: The results showed significant differences between marital status, age groups, and work experience across different occupations, while no significant differences were found based on education level. The highest mean score of the mental workload subscales was related to the physical demand subscale, while the lowest was related to the frustration subscale. Significant differences were observed in the scores of mental workload subscales across different job categories, but no significant differences were found in the scores of physical and mental fatigue dimensions across job types. All mental workload subscales, except for performance, had a direct correlation with physical and mental fatigue dimensions, while the performance subscale showed an inverse relationship.

Conclusion: The findings of this study emphasize the importance of a more precise understanding of the relationship between mental workload and fatigue in workplace environments and could contribute to improving working conditions and the quality of life for employees in small industries