The crystal structure of the phase alpha-SnCu2FeS4, has been examined by EDX and electron and X-ray difraction techniques. This compound crystallizes in the tetragonal space group P4 (No. 81) with a=c= 541.4 (4) pm, Z=1, and it is a derivative structure of the basic sphalerite structure. The refinement of the structure converged to the final agreement index R(F)=0.060.