​In order to assess the potential of Zr-based alloys as biomedical superelastic alloys compatible with magnetic resonance imaging (MRI), novel Zr–Nb–Al alloys were designed. The effects of Nb and Al contents on constituent phases, crystallographic and microstructural characteristics and superelastic properties were investigated. The range of compositions that exhibit shape memory effect and/or superelasticity was clarified. The maximum value of the superelastic recovery strain increased with the increase of Al content, reaching a maximum value at 8 at.% Al, after which a decline was observed as Al content was further increased. A large transformation strain in a range of 7.3–7.6 % was found to be achievable along the []β direction in the compositions exhibiting superelasticity by considering the transformation strain calculated using the lattice constants of the β and martensite phases. The composition dependence of superelastic recovery strain was analyzed according to microstructure, orientation dependence of transformation strain and recrystallization texture. Al was found to be effective in suppression of the athermal ω phase and BCT phase. Zr–9Nb–8Al alloy exhibited an optimal combination of a large superelastic strain of 4.3 % and a low magnetic susceptibility of 1.67 × 10−6 cm3g−1. Large superelastic strains of the Zr–9.5Nb–7Al and Zr–9Nb–8Al alloys are attributed to the development of a favorable {001}β<110>β recrystallization texture and the suppression of both athermal ω phase and BCT phase.​