A morphological (histological) study of the stomach (proventriculus and gizzard) of the red-capped cardinal (Paroaria gularis gularis) was carried out, under light microscopy. Anatomically, the stomach of the red-capped cardinal is constituted by two externally distinguishable chambers: a cranial region, glandular, the proventriculus (proventriculus, pars glandularis), which is cranially connected to the esophagus and caudally, to the gizzard or ventriculus (ventriculus, pars muscularis), also known as muscular portion. Both, the mucous tunic of the proventriculus and of the gizzard present folds lined by simple prismatic epithelium. A thick cuticle is laid over the mucous tunic of the gizzard. In the lamina propria of both regions, there are simple tubular glands. The submucosa of the proventriculus is occupied by deep proventriculus glands. Due to the absence of a muscularis mucosae, the submucosa of the gizzard cannot be distinguished from the lamina propria. The muscle tunic of proventriculus, consists of a inner longitudinal layer, of an intermediary circular layer and of an external longitudinal discontinuous layer of smooth muscle. In the gizzard, it consists of an internal longitudinal layer and of an external circular layer. In both chambers, the serosa is constituted by a connective tissue lined by mesothelium, containing blood vessels, nerve elements of the serous plexus and adipose tissue