Background: There are data suggesting that low dose radiation induced inflammatory reactions and changes of the immune system could be responsible for late circulatory and other chronic diseases. Chronic low dose radiation of occupationally exposed persons requires careful examination of their immune status. The purpose of this survey was to study some immunological parameters and serum proteins as suitable markers for screening cardiovascular diseases and chronic inflammatory state in NPP personnel. Materials and Methods: Lymphocyte populations were determined using four parameters by flow cytometer. Plasma levels of interleukin IL6, CRP and INFγ were determined by ELISA. Results: The main T lymphocyte populations did not show any differences to controls but there were trends of increasing activated CD3 HLA, CD4+25+ and CD8+38+ T lymphocytes and  CRP and IL6 markers. Higher, but not significant averages were recorded for regulatory T lymphocytes probably due to their role in preventing of atherosclerosis. No dependence was established of the studied parameters to cardiovascular or other chronic diseases, a weak correlation was only recorded for IL6 with autoimmune ones (p=0.042). The results show that the age, obesity, and other lifestyle factors, particularly cigarette smoking could be considered as cofounder for circulatory diseases. Conclusion: It could be assume that radiation induced aging of T cells and activation of inflammatory response are partly involved in the development of inflammatory chronic diseases as the more pronounced deviations in the parameters are observed with increasing age and cumulative dose.