Thioredoxin glutathione reductase from Schistosoma japonicum (SjTGR), a multifunctional enzyme, plays a vital role in antioxidant pathways and is considered to be a potential drug target for the development of antischistosomal chemotherapy. In this study, two constructs of a truncated form of SjTGR without the last two residues (Sec597–Gly598) were cloned, overexpressed and purified using wild‐type and codon‐optimized genes. Only SjTGR from the wild‐type gene was found to form a complex with flavin adenine dinucleotide (FAD), which could be crystallized in the orthorhombic space group P212121, with unit‐cell parameters a = 84.185, b = 86.47, c = 183.164 Å, at 295 K using the hanging‐drop vapour‐diffusion method. One dimer was present in the crystallographic asymmetric unit and the calculated Matthews coefficient (VM) and solvent content were 2.6 Å3 Da−1 and 52.8%, respectively. Structural determination of SjTGR is in progress using the molecular‐replacement method.