Data underlying the figures shown in the publication 'Composition dependence of bulk superconductivity in YFe2Ge2', including resistivity and heat capacity versus temperature for different sample qualities, in zero and 2.5 T applied field, resistive transition temperature vs. residual resistivity for a large number of samples, transition temperature and residual resistance ratio vs. nominal composition, lattice parameters vs. nominal composition, and EDS-derived phase content of polycrystalline ingots from with varying nominal composition.