Ytterbium alkali-metal chromites YbMCr2O5 (M = Li, Na, K, Cs) were synthesized by a ceramic procedure from the corresponding oxides and carbonates. Their crystal systems and unit cell parameters were determined by the homology method: for YbLiCr2O5, a = 10.34 Å, b = 10.62 Å, c = 15.05 Å, Z = 16, Vo = 1653.74 Å3, ρX-ray = 5.85 g/cm3, ρpycn = 5.81 ± 0.03 g/cm3; for YbNaCr2O5, a = 10.30 Å, b = 10.56 Å, c = 16.46 Å, Z = 16, Vo = 1790.32 Å3, ρX-ray = 5.64 g/cm3, ρpycn = 5.59 ± 0.07 g/cm3; for YbKCr2O5, a = 10.33 Å, b = 10.63 Å, c = 19.93 Å, Z = 16, Vo = 2188.47 Å3, ρX-ray = 5.95 g/cm3, ρpycn = 5.91 ± 0.03 g/cm3; and for YbCsCr2O5, a = 10.34 Å, b = 10.63 Å, c = 18.43 Å, Z = 16, Vo = 2025.72 Å3, ρX-ray = 5.19 g/cm3, ρpycn = 5.16 ± 0.05 g/cm3.