This cross-sectional study of stable HIV-infected children was designed to document the immunological manifestations of paediatric HIV infection and to determine whether inexpensive markers of immunosuppression could be identified. Investigations included lymphocyte count and subset analysis, levels of total protein, albumin, immunoglobulins, beta-2 microglobulin and neopterin. The median age of the 74 children studied was 16.5 months and 76% and 39% had subnormal percentage CD4+ counts and absolute CD4+ counts, respectively. According to the Centers for Disease Control (CDC) guidelines, 85% were moderately or severely immunosuppressed. The majority had elevated neopterin, beta-2 microglobulin, IgG, IgM and IgA concentrations. The IgG concentration correlated positively with total globulin, IgG1 and IgG3 concentrations. On bivariate analysis, the absolute CD4+ count correlated positively with total lymphocyte count (r = 0.28 < 0.48 < 0.64) and negatively with total IgG concentration (r = -0.47 < -0.27 < -0.04), IgG1 concentration (r = -0.51 < -0.31 < -0.08), and neopterin concentration (r = -0.49 < -0.28 < -0.04). There was no correlation between CD4+ count, total globulin or beta-2 microglobulin concentration. On multiple linear regression analysis only the total lymphocyte count correlated with CD4+ count. Furthermore, on bivariate analysis total lymphocyte count correlated positively with absolute CD8+ count (r = 0.82 < 0.88 < 0.92). In conclusion, although there was a positive correlation between absolute CD4+ count and total lymphocyte count, the clinical significance is questionable as the total lymphocyte count correlated more strongly with the absolute CD8+ count.