During the synthesis by flux evapn. in KCl at 930° of KCrIIPO4, oxidn. of Cr(II) was obsd., leading to the formation of KCrIIIP2O7. The crystal lattice of KCrP2O7 is monoclinic, space group P21/c with a = 7.3470(7), b = 9.9090(10), c =8.1730(8)Å, β = 106.806(11)°, Z = 4 and V = 569.59(10) Å3, F(000) = 516, 1981 obsd. reflections with I > 3σ(I), R = 0.023, Rw = 0.026. The magnetic susceptibility was measured between 3.6-300 K at different magnetic field strengths. The neg. value of the Curie-Weiss temp. and the behavior of magnetic susceptibility indicate an antiferromagnetic spin order in this compd. with a Neel temp. TN = 8.5 K.