The small bacterial laccase from the actinobacterium Streptomyces coelicolor which lacks the second of the three domains of the laccases structurally characterized to date was crystallized. This multi-copper phenol oxidase crystallizes in a primitive tetragonal lattice, with unit-cell parameters a = b = 179.8, c = 175.3 A. The crystals belong to either space group P4(1)2(1)2 or P4(3)2(1)2. The self-rotation function shows the presence of a noncrystallographic threefold axis in the structure. Phases will be determined from the anomalous signal of the natively present copper ions.