To evaluate serum chemokines, macrophage inflammatory protein (MIP)-1 alpha, MIP-1 beta and RANTES, concentrations in non-progressing HIV-infected patients and AIDS patients. University Hospital-based AIDS Clinical Trials Unit. Serum MIP-1 alpha, MIP-1 beta and RANTES levels were determined by enzyme-linked immunosorbent assay using archived serum specimens obtained on two occasions at least 1.8 years apart. Long-term non-progressing HIV-infected adult patients were identified from clinic records. For each non-progressing patient two adult AIDS patients with initial documentation of seropositivity the same year and the same length of follow-up were selected. Four long-term non-progressing patients and eight AIDS patients were studied. Neither the duration of known HIV positivity at the time of specimen collection nor the length of time between specimen collections differed significantly between non-progressing patients and AIDS patients. Serum levels of MIP-1 alpha, MIP-1 beta and RANTES in specimens obtained either early or later in the course of HIV infection did not differ significantly between non-progressing patients and AIDS patients. In the two patient subsets, significant differences in serum chemokine levels over time were not observed. The rate of change of serum chemokine concentration over time also did not differ between non-progressing patients and AIDS patients. Serum MIP-1 alpha and MIP-1 beta levels did not reach levels reported to suppress HIV proliferation in vitro. When expressed as a quantity per peripheral blood CD8+ lymphocyte, AIDS patients exhibited significantly greater levels of MIP-1 alpha, MIP-1 beta and RANTES than non-progressing HIV patients (P < 0.05). These values did not exhibit a significant variation over time. Serum MIP-1 alpha, MIP-1 beta and RANTES levels do not distinguish patients with AIDS from patients with non-progressing HIV infection. Variations in levels of these chemokines do not explain individual variation in the natural history of HIV infection.