This study investigated the mental health status of personnel of an industrial complex. Subjects (N=411), were selected through cluster sampling and were administered the SCL-90-R. The mean age of the sample was 39.6 with a mean of 17.7 years of service. The majority of the subjects were men (95.5%), were employed as technical workers (94.6%) and had elementary level education (36.5%), Data were analyzed by X2, t-test and analysis of variance. The results showed that 37.96% of the subjects obtained scores above the cut off point, indicating the presence of possible illness. Most of their complaints were of somatic nature and anxiety. Although a big proportion of this group had ages between 31 to 40, with 11 to 20 years of service, married and women, with elementary education, but there was no significant difference between these variables and mental disorders.