Acute phase proteins (APP) are plasma proteins secreted by the liver following inflammation. APP reference levels are unknown for healthy female Zaireans. The purpose of this study was to determine: (a) the reference levels of alpha 1-acid glycoprotein (AGP), C-reactive protein (CRP), ceruloplasmin (Cp), and haptoglobin (Hp) in healthy Zairean adult women, and (b) whether the levels are different between lactating (Group I), pregnant (Group II) and non-pregnant/non-lactating women (Group III). APP were measured by radial immunodiffusion in 180, 212 and 27 women of Groups I, II, and III respectively (age range 15-45 years). The ranges for different APP were wider than for Western adults or those obtained in plasma from normal laboratory personnel. The means and medians of AGP were lower in pregnant that non-pregnant women, and those of CRP and Cp were higher. There were no differences in mean Hp levels between the three groups. In non-pregnant women, the mean levels and 95% confidence limits of CRP, Cp and Hp were within published ranges for healthy Western adults, while those of AGP were higher. In pregnant women only AGP and Hp were within published ranges. We conclude that, at least in non-pregnant women, the same cut-off points of CRP, Cp and Hp used for Western adults may also be used in the assessment of inflammation in Zairean women.