The transforming behavior of Fe doped Ni 55 Mn 20 Ga 25 ferromagnetic shape memory alloys is investigated in this study. The Ni 55 Mn 20 Ga 25 alloy only undergoes P (parent phase)→non-modulated T (non-modulated tetragonal martensite) martensitic transition. It does not exhibit intermartensitic transition, since the non-modulated T structure is the most stable martensitic state in Ni–Mn–Ga system. However, 2% (at.) Fe substitution for Ni of the Ni 55 Mn 20 Ga 25 alloy induces an intermartensitic transition and the transition sequence of Ni 53 Fe 2 Mn 20 Ga 25 alloy changes into P (parent phase)→7M (seven-layer modulated martensite)→non-modulated T. It was also found that the intermartensitic transition of Ni 53 Fe 2 Mn 20 Ga 25 alloy can be suppressed by the internal stress produced by water quenching and sample crushing. This is considered to stem from the inhomogeneous and non-directional internal stress states generated during water quenching and sample crushing process.