The present contribution deals with the histochemical mapping of the distribution of acid and alkaline phosphatases and succinic dehydrogenase in the medulla oblongata and spinal cord of mouse. The acid phosphatase is observed in neurons of all the nuclei except nucleus cervicalis lateralis (NC), though the activity varies from intense to moderate. Only one nucleus, i.e., nucleus parvocellularis compactus (NPC) is midly positive. In alkaline phosphatase preparations most of the nuclei are either intensely positive or moderately positive. Few nuclei are midly positive. It is interesting to note that only two nuclei, i.e., area postrema (AP) and nucleus cervicalis lateralis (NC) are negative for this enzyme. Further the reaction in most of the nuclei is diffused. In the case of succinic dehydrogenase out of 36 nuclei studied, 9 nuclei are intensely positive, 11 areas are moderately positive, 7 are mildly positive and 9 are completely devoid of enzymatic activity. Nucleus reticularis superior demonstrates activity of very high order. The distribution of the above enzyme has been co-related with the functional significance of the various nuclei.