Baseline values for total and selected regional blood flows are presented for 77 studies of baboons from 92 days of gestation to 61 days of postnatal age. Systemic blood flow rose from 231.3 +/- 21.4 ml/min/kg to 330.4 +/- 122.4 ml/min/kg in late gestation and from 124.0 +/- 29.9 ml/min/kg on day 1 to 162.8 +/- 20.5 ml/min/kg at the 8th week. In both fetal and infant periods, blood flow to brain, heart, kidneys, and gastrointestinal tract changed to reflect both anatomic and functional requirements. When compared to late gestation levels, blood flows on day 1 to brain, myocardium and gastrointestinal tract decreased proportionally to systemic blood flow. In contrast, renal blood flow on day 1 was maintained at the predelivery level and represented about twice the proportion of systemic blood flow of late gestation. The data presented provide a developmental profile of systemic and selected organ blood flows from mid-gestation to the 8th week of postnatal life in the baboon. As such, they may form the basis for further investigation and understanding of perinatal maladaptation from preterm delivery and disease.