Wnt signalling has several roles during heart development, which involve both inhibition of cardiogenesis by canonical Wnt/ß-catenin signaling and stimulation by non-canonical Wnt11/JNK signaling. Here, we use stem-cell-like embryonic explants from Xenopus laevis to investigate the timing of Wnt molecules function and the molecular basis of the regulatory mechanisms involved. We uncover a central role for GATA transcription factors in integrating and regulating Wnt signaling in cardiogenesis. GATA gene expression emerges as the relevant target for inhibition by canonical Wnt/ ß-catenin signaling, since experimentally reinstating GATA function overrides ß-catenin–mediated inhibition and restores cardiogenesis. GATA transcription factors in turn directly regulate not only Nkx2-5 but also Wnt11. We show that Wnt11 function is indeed required to a large extent for mediating the cardiogenesis-promoting activity of GATA transcription factors. These results demonstrate that GATA transcription factors occupy a central position between canonical and non-canonical Wnt signaling in a pathway regulating heart muscle differentiation.