Human gastric organoids (HGOs) are 3-D cultures of primary gastric epithelial cells that serve as in vitro models for gastric epithelial physiology, development, and disease. The extracellular matrix material that organoids are maintained in provides crucial signals to the epithelial cells, regulating their function and growth. We here describe the application of human gastric ECM (hgECM) for HGO cultures, to provide a tissue- and species-specific growth matrix.