Microfilter absorbed whole blood samples from 223 Tanzanian babies and 189 adults from Cameroon have been examined. Blood specimens are difficult to obtain from African suburban and rural areas, and lack of storage and transportation facilities can prevent the collection of samples. We evaluated some microassays employing whole blood collected on filter paper. This method is a well established technique in neonatal screening for endocrinometabolic diseases. We also developed microassays for whole dried blood spots to type AB0 blood groups and HIV disease using commercial reagents. Phenotype and gene frequencies for AB0 and hemoglobin systems as well as our results concerning the typings of thyroxine (T4), thyroid stimulating hormone (TSH), human immunodeficiency virus (HIV) and hepatitis B virus (HBV) are reported.