Fatigue is one of the main factors of workers' accidents in construction. This study aimed to find out the fatigue conditions of PT. X construction workers. Using crosssectional design and Industrial Fatigue Research Committee Questionnaire, it was found that 100 percent of workers experience fatigue before and after work, with the prevalence of fatigue above low increased after working from 52.5 to 69.3 percent, meaning that further assessment and improvement were needed. The study found, working time (p = 0.02) and water consumption (p = 0.05) are risk factors that have significant correlation with worker's fatigue. Control measures that had been done were limiting the overtime hours, providing temporary shelter, and regular exercise.It was suggested to tighten the policy of working hours, promote healthy lifestyle, and control working environment factors.