Lymph nodes from homosexual men with persistent generalized adenopathy were evaluated for distributions of T-cell phenotypic subsets and surface immunoglobulin (SIg)-bearing lymphocytes. Electron microscopy revealed tubulovesicular structures within lymphocytes but no multivesicular rosettes. Eight to 33 per cent of the lymphocytes within germinal centers were supressor T cells, compared with germinal centers from control lymph nodes, in which these cells were rare ( P=0.002). Significantly greater percentages of suppressor/cytotoxic T lymphocytes were also present in the paracortex and follicular mantles of lymph nodes from the homosexual group ( P=0.002 and 0.007, respectively). Percentages of helper T lymphocytes were significantly decreased in germinal centers ( P=0.008) and paracortical regions ( P=0.002). Florid follicular hyperplasia with aberrations in follicular architecture was the most common histologic pattern, but one node with diffuse hyperplasia and subtotal effacement of architecture revealed depletion of SIg-bearing lymphocytes and increased numbers of suppressor T cells. Reversed helperto-suppressor T-cell ratios in lymph nodes from homosexuals with generalized adenopathy may be related to viral infection and contribute to immune deficiency in this group.