Plethodontid terrestrial salamanders are emerging models in the study of the evolution of chemical communication in vertebrates. Their vomeronasal system is well defined. It comprises sensory neurons in the epithelium of the vomeronasal organ, whose axons form  the vomeronasal nerve projecting to the accessory olfactory bulb (AOB), which in turn  projects to the vomeronasal amygdala through the accessory olfactory tract. A detailed  description of the cellular elements of the urodele AOB is lacking. Neuronal morphology in the AOB was studied by means of biocytin intracellular injections and retrograde tract tracing  in the salamander Plethodon shermani. The AOB exhibits the characteristic lamination of  olfactory bulbs, except that it displays a mixed periglomerular and mitral somata layer  superficially. Mitral cells are the only AOB neurons projecting to the vomeronasal amygdala.  Each mitral cell sends multiple axonal branches, generally through both dorsal and ventral portions of the accessory olfactory tract. Some mitral cells additionally send axon collaterals  in the white matter immediately ventral to the AOB. AOB interneurons are divided into  superficial periglomerular and deep granule cells, each category exhibiting morphological  variety. Some neurons in the granule cell layer of the AOB or the region ventral to the AOB  have dendritic trees that cover both regions. The present study is the first to highlight the full anatomical extent of single AOB neurons and surprisingly suggests that the ventrolateral telencephalon found below the AOB is part of the salamander vomeronasal system.