X-ray powder diffraction data for Ba0.5Sr0.5Co0.8Fe0.2O3−δ are reported. The powder was prepared using a metal-EDTA complexing method. The XRD data could be fitted with a primitive cubic unit cell in space group Pm3m (No. 221). The Rietveld refined unit cell parameter is ac=0.398 30(3) nm with Z=1 and Dx=5.75 g/cm3.