IL-13 mediates its effects through a complex receptor system including IL-4R alpha and a functional IL-13R alpha1. IL-13 has been reported to have no effects on mouse B cells due to a lack of receptor expression. However, on human B cells a functional IL-13R alpha1 has been described. Here, we identified the rat IL-13R alpha1 in order to analyze its expression and function in rat B cells. The expression of IL-13R alpha1 has been shown by the presence of mRNA and the corresponding protein in purified rat B cells and in rat hybridoma B cell line. Rat B cells are able to bind IL-13 and to proliferate when cultured with CD40 ligand and IL-13. In vivo experiments showed that administration of IL-13 did enhance IgE production. These results suggest a direct interaction of rat B cells with IL-13 through a functional receptor with an increase of IgE production and provide a relevant model to further study the activity of IL-13 and to better understand its role in human diseases.