X-ray powder diffraction data for Mo2.85Al1.91Si4.81 are reported. The new Mo2.85Al1.91Si4.81 compound was successfully prepared using the self-propagating high-temperature synthesis (SHS) technique. The starting atomic mixture of reactant powders was Mo+2(1−x)Si+2xAl with x=0.3. The final powder compound obtained by the SHS technique was determined to be Mo2.85Al1.91Si4.81 by ICP-AES. X-ray powder diffraction pattern of Mo2.85Al1.91Si4.81 was recorded using an X-ray powder diffractometer, Cu Kα radiation, and analyzed by automatic indexing programs. Mo2.85Al1.91Si4.81 was found to be hexagonal with a=4.6929(2) Å and c=6.5515(4) Å. The XRD results are in good agreement with those of Mo2.85Ga2Si4.15.