Bovine mesenteric lymphatic vessels have nerves in their walls which in response to field stimulation cause an increase in freqency of spontaneous lymphatic contractions and this could be blocked by α-antagonists. When vessels were loaded with [3H]-noradrenaline, 3H-effiux was increased in response to field stimulation and this was potentiated by α2-antagonists and depressed by α2-agonists. Electrical activity in these vessels consisted of a single action potential which preceded each contraction. Mean resting potential was –61 mV ± 5.7 (SD). Stimulation of postsynaptic α-receptors caused a depolarization accompanied by a decrease in membrane conductance while β-receptor stimulation had the opposite effect. Lymphatic noradrenergic nerves appear to have a role in the living animal since stimulation of the sympathetic chain in anaesthetized sheep increased popliteal efferent lymph flow and this could be blocked by α-adrenergic blockers.