ArsR is a member of the SmtB/ArsR family of metalloregulatory proteins that regulate prokaryotic arsenic-resistance operons. Here, the crystallization and preliminary X-ray diffraction studies of a cysteine-free derivative of ArsR from Corynebacterium glutamicum (CgArsR-C15/16/55S) are reported. CgArsR-C15/16/55S was expressed, purified, crystallized and X-ray diffraction data were collected to 1.86 Å resolution. The protein crystallized in a tetragonal space group (P4), with unit-cell parameters a = b = 41.84, c = 99.47 Å.