Introduction. Physical development, physiological pre-morbid shifts, morbidity on demand, morbidity with temporary loss of working capacity, occupational morbidity, production-related morbidity, disability at working age, mortality at working age, the course and outcomes of pregnancy and childbirth in female workers, the health of children of the first 3 years of life in female workers - all these are indicators used by specialists to assess the health of working collectives in relation to working conditions. Health assessment based on one or two indicators does not provide a comprehensive picture of the state of health. In this connection, a complex of indicators is needed, which will require great organizational efforts and material and financial expenditures at the same time. Human immunity can become an integral indicator. It is primary in relation to secondary indicators of health, such as morbidity, disability, mortality and others. Thus, the most accessible indicator can be considered the intensity of specific immunity against tetanus and diphtheria. It is quantitatively determined by the titer of antibodies to anti-tetanus and anti-diphtheria anatoxin. Objective: to study the state of tetanus and diphtheria immunity in workers of an ammonia and urea production plant as a criterion for assessing the impact of working conditions on the health of workers. Materials and methods: statistical analysis of morbidity with temporary disability, chronic accumulated pathology, indicators of preservation of postvaccinal tetanus and diphtheria immunity in 971 “year-round” workers of modern ammonia and urea production was carried out. Results of the study: it was found that the loss of specific immunity correlates closely (r=+1.0) with the increase in the incidence of morbidity with temporary disability and chronic accumulated pathology. The highest levels of loss of specific anti-tetanus and anti-diphtheria immunity, morbidity with TST, chronic accumulated pathology have female workers, workers from repair and maintenance group, aged 50-59 years, with experience of 20 years and more, as well as persons employed in the professions of List № 1 and List № 2, according to the Decree of the Cabinet of Ministers of the USSR from 26. 01.1991 N 10 (ed. of 02.10.1991) “On Approval of the List of industries, works, professions, positions and indicators entitling to preferential pension provision”. Conclusions: the state of tetanus and diphtheria immunity in workers is closely correlated with the level of morbidity with UTI and chronic accumulated pathology. This indicator can serve as an alternative method of studying the health status of workers at industrial enterprises.