The structure of the new mixed valence compound Ba2F2Fe1.5S3 was solved by means of single crystal X-ray analysis. It crystallizes in an orthorhombic cell, in the Pnma space group with the cell parameters a = 12.528(3) angstrom, b = 18.852(4) angstrom, and c = 6.0896(12) angstrom. The structure is formed by the alternated stacking of fluorite type [Ba2F2](2+) blocks and the newly discovered [Fe1.5S3](2-) blocks. This [Fe1.5S3](2-) block exhibits a mixed valence of iron with Fe(+II) located in octahedrons and Fe(+III) in tetrahedrons. Preliminary susceptibility measurements suggest a low dimensional antiferromagnetic behavior.