The effect of alloy stoichiometry and boron doping on the H 2-induced environmental embrittlement of Ni 3Fe intermetallic alloys was investigated at room temperature. The results show that the alloy stoichiometry of Ni 3Fe does not affect the sensitivity to hydrogen embrittlement and that the H 2-induced environmental embrittlement is also not related to the surface elemental segregation induced by long time ordering. The results also indicate that the boron doping can effectively suppress the H 2-induced embrittlement of ordered Ni 3Fe intermetallics. The beneficial effect of boron is believed to be due to its strong segregation to grain boundaries and the enhancement of the boundary cohesive strength of Ni 3Fe alloys.