Xfinis aKrüppel‐type zinc finger protein characterized by the highest number of zinc finger motives (37) found to date. An interesting feature of this protein is the cytoplasmic location, coupled byin vitroRNA binding activity: both these properties may suggest a role forXfinin RNA metabolism. As the corresponding mRNA, the protein product ofXfinis part of the maternal store inXenopusand is present throughout embryogenesis. We usedin situhybridization to establish the expression pattern ofXfinin developmental stages. We show here that it is expressed evenly throughout gastrula and neurula stages embryos, while in later stages its transcripts are mainly enriched in the endoderm. In addition, we performed somein vivoperturbation experiments. We found that overexpression ofXfinby injection of synthetic mRNA in earlyXenopusembryos causes disruption of posterior development; also,Xfinoverexpression inhibits the normal expression of the pan‐mesodermal markerXbra.