Streptococcus suis, an important zoonotic pathogen, expresses immunoglobulin G-binding protein, which is thought to be helpful to the organism in eluding the host defence system. Recombinant IgG-binding protein expressed in Escherichia coli has been crystallized using the hanging-drop vapour-diffusion method. The crystals belonged to space group P2(1)2(1)2(1), with unit-cell parameters a = 38.98, b = 43.94, c = 78.17 A and one molecule in the asymmetric unit. Diffraction data were collected to 2.60 A resolution.