We compared the absolute CD4+ count, at different CD4+ percentages (CD4%), between Asian (n=442) and Caucasian (n=674) untreated HIV-infected individuals, using linear regression methods. At any given CD4%, Asians had lower CD4+ count than Caucasians (p=0.001). The difference varied from 38.9 cells/mm3 (95% CI: 3.3-74.5 cells/ mm3 ) at CD4% of 15% to 108.7 cells/mm3 (95% CI: 42.5-174.9 cells/mm3 ) at CD4% of 40%. The impact of these differences on prognosis is uncertain, but it may be that the prognostic thresholds for CD4+ count used in Caucasian populations are inappropriate in Asian populations.