Experiments were performed to investigate whether local cooling facilitates adrenergic neurotransmission in the cutaneous vein of the dog. Helical strips of saphenous veins were incubated with <sup>3</sup>H-noreρineρhrine and mounted for isometric tension recording and superfusion. The superfusate was collected for measurement of total radioactivity or for chromatographic analysis. Electrical stimulation (2 Hz) caused contraction and augmented the efflux of <sup>3</sup>H-norepinephrine and metabolites. Cooling (from 37 to 28 °C) imposed during electrical stimulation caused a further increase in tension, but decreased the amount of <sup>3</sup>H-norepinephrine and metabolites overflowing into the superfusate. These experiments demonstrate that the potentiating effect of cooling on the response of cutaneous veins to sympathetic nerve stimulation is not associated with facilitation of adrenergic neurotransmission. It probably is due to an altered sensitivity of the vascular smooth muscle to the transmitter.