The melanin-concentrating hormone (MCH) family of neuropeptides is believed to be important in controlling certain feeding behaviors. This family consists of one ligand, melanin-concentrating hormone (MCH), and two receptors, melanin-concentrating-1 receptor (MCH-1R) and melanin-concentrating-2 receptor (MCH-2R), of which only MCH-1R is expressed in rodents. Recently, the distribution of MCH-1R in rat brains was published revealing that it is expressed throughout the rat brain in a complex and widespread manner. Moreover, mice lacking MCH and MCH-1R have been generated and have been found to be leaner and more active than their wild-type littermates. Consequently, MCH-1R has become a possible site for pharmacological interaction to control obesity. Many of these experiments are being performed utilizing mice however, the areas expressing MCH-1R in the mouse brain still remain unknown. Therefore, in situ hybridization was performed in both mouse and rat brain samples to elucidate the MCH-1R mRNA expression in the mouse and to compare these results with the expression in the rat. This comparison study revealed that most of the positive nuclei evaluated were represented in both rodent models and that these areas displayed similar expression intensities. However, a subset of nuclei was found to display a different MCH-1R expression between these two rodent species. These expression differences reside in brain areas important in reward, motivation, movement, visualization, vigilance, and learning, and could possibly explain differences in feeding and foraging behaviors between mice and rats.