The first sodium uranyl chromate, Na 4 [(UO 2 )(CrO 4 ) 3 ], has been obtained by high-temperature solid-state reaction. The structure (triclinic, P1, Z ϭ 2, a ϭ 7.1548(3), b ϭ 8.4420(3), c ϭ 11.5102(5) Å , α ϭ 80.203(1)°, β ϭ 79.310(1)°, γ ϭ 70.415(1)°V ϭ 639.24(4) Å 3 ) has been solved by direct methods and refined on the basis of F 2 for all unique reflections to R1 ϭ 0.024 [calculated on the basis of 4374 unique observed reflections (ΗF o Η Ն 4σ F )]. The structure is based on chains of composition [(UO 2 )(CrO 4 ) 3 ] that are parallel to [101]. The chains contain UrO 5 pentagonal bipyra-