DyCo2B2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Dy3+ is bonded in a body-centered cubic geometry to eight equivalent B3- atoms. All Dy–B bond lengths are 2.88 Å. Co+1.50+ is bonded to four equivalent B3- atoms to form a mixture of distorted edge and corner-sharing CoB4 tetrahedra. All Co–B bond lengths are 2.00 Å. B3- is bonded in a 4-coordinate geometry to four equivalent Dy3+ and four equivalent Co+1.50+ atoms.