We determined dopamine (DA), noradrenaline (NA), and adrenaline (A), as well as immunohistochemically stained tyrosine hydroxylase (TH) and DA in dissected rat ventral mesencephalon (VM) tissue from Embryonic Day (ED) 14 to Postnatal Day (P) 17. Whole VM tissue DA, NA, and A contents increased with advancing age. VM DA/protein increased from ED15 to ED16, whereas NA/protein increased from ED15 to ED16 and from ED20 to P4. VM DA/NA ratio increased from ED14 to ED15 and decreased from ED18 to P4. VM cell suspensions exhibited higher DA/NA ratios than whole VM tissue. Washed cell suspensions had higher DA/NA than unwashed counterparts. We conclude that data from both VM immunohistochemistry and catecholamine assays relate to VM development. VM DA is contained mainly in cells, whereas VM NA is located in fibers that channel at the dorsal side of the VM. Determination of tissue catecholamine contents may be helpful for the biochemical characterization of tentatively identified VM grafts.