A valid scientific evaluation of the efficacy of human immunodeficiency virus (HIV) vaccines or antiretroviral drugs (ARV) includes measurement of changes in physiological parameters of subjects from known established baseline reference ranges. This study was designed to establish reference ranges for biochemical parameters among healthy adult Cameroonians to support planned HIV vaccine clinical trials and scaling up of ARV among AIDS patients. After informed consent, blood and urine samples were collected from a total of 576 adult Cameroonians and analyzed for the presence of underlying pathologies that may affect biochemical parameters. Samples from 501 of them were found eligible for the determination of reference biochemical parameters. After complete assay, the data were subjected to both parametric and non parametric statistics for analyses, with 2.5 and 97.5 percentiles considered as the lower and upper limits of reference ranges. There were 331 (66.1%) males and 170 (33.9%) females, with 359 (71.7%) and 142 (28.3%) of them residing in the urban and rural areas respectively. The ranges for biochemical parameters got were: SGOT: 8.7 - 40.7 IU/l ; SGPT: 5.2 - 29.1 IU/l ; Alkaline Phosphatase: 52.6 - 251.1 IU/l; Creatinine: 0.2 - 2.2 mg/dl; Total Protein : 46.9 - 107.4 g/l; Albumin : 30.1 - 65.2 g/l; Triglyceride : 0.1 - 3.5 g/l; HDL Cholesterol : 54.5 - 172.0 mg/dl; LDL Cholesterol: 12 - 190 mg/dl; Total Cholesterol 0.9 - 3.2 g/l; Total Bilirubin: 0.4 - 3.3 mg/dl; and Direct Bilirubin : 0.1 - 1.2 mg/dl. These ranges are compared to ranges presently used in various clinical laboratories in Cameroon.