The histochemical fluorescence technique of Falck and Hillarp was used to examine the distribution of catecholamine-containing varicostities within the hypothalamus of the rhesus monkey (Macaca mulatta). Varicosities were seen in heaviest concentrations within the periventricular area and the following nuclei: lateral and madial preoptic, supraoptic, paraventricular, arcuate and dorsomedial. Patterns observed presented striking similarities and dissimilarities to catecholamine distribution reported in the rat and car. Catecholaminergic perikarya were not observed routinely.