Mn 1 + 2 s Cr 2 − 3 s Sb s O 4, a new series of spinels, have been prepared and studied using X-ray powder data. For s going from 0.05 to 0.30, a gradually increases from 8.441(1) to 8.472(1) Å, and u slightly decreases, from 0.262 to 0.258. Interatomic distances are given. The Mn 1 + 2 s Cr 2 − 3 s Sb s O 4 (0.05 < s < 0.30) series may be conceived as the result of partial substitution of Cr 3 + by 2/3Mn 2 + + 1/3Sb 5 + in the normal spinel, MnCr 2O 4.