To assess the mental disturbances induced by accidents at work, 41 male workers who had witnessed a fatal work accident were evaluated utilizing the criteria for posttraumatic stress disorder (PTSD) from the ICD-10 Classification of Mental and Behavioral Disorders. The Hamilton Depression Rating Scale (HDRS) was also administered to the exposed workers, as well as to 47 non-exposed construction-worker controls. The two groups were well matched with respect to age, years of employment, and years of education. They were all of Han sect; and lifestyles, incomes, and living conditions were similar. The exposed workers had a high rate of PTSD: 11 of 41 (26.8%) at one month and five of 39 (12.9%) four months after the fatal accident. The exposed groups' scores for depressive symptoms were significantly higher than those of the controls, including: 1) depressed mood, 2) guilt, 3) initial insomnia, 4) middle insomnia, 5) delayed insomnia, 6) decreased interest in work and other activities, 7) anxiety, 8) somatization, and 9) gastrointestinal symptoms (p < 0.05, p < 0.01, p < 0.001). Fatal work accidents, a major hazard in the construction industry, affect not only the victims but also the mental health of other workers. PTSD and associated emotional disorders related to exposure to serious work accidents deserve more attention for clinical and research purposes.