Sixty seven immunocompromised patients were studied prospectively to observe the association of Cytomegalovirus (CMV) pp65 antigenemia with CD4+ T-lymphocyte count, a marker of cellular immunity. This study was conducted in three different groups of immunocompromised patients including HIV infected patients, patients with haematological malignancy and kidney transplanted patients. Result of the study indicate that proportion of severely immunocompromised patients having lower cellular immunity (< or = 200/microl) in all the three groups were comparable and ranged from 44% to 50%. The study also indicated that high prevalence of CMV pp65 antigenemia was associated with lower level of cell mediated immunity (< or = 200/microl). pp65 antigen was detected in 40% of patients with low immunity in contrast with 20% and 22.72% in the patient with intermediate immunity and in group without gross immune deficiency respectively. Lower level of cellular immunity was also associated with high level of CMV pp65 antigen. This was indicated by 75% patients with low immunity having high level of CMV pp65 antigen. It may perhaps be concluded that CMV infection occurred in a higher rate in immunocompromised patients and this is highly associated with the lower immune status of the immunocompromised patients as well as the level of CMV pp65 is higher in the patients with lower cellular immunity. This perhaps indicate that CMV infection is more severe in patients with low cellular immune response.