The crystal structure of anion-deficient hexagonal perovskite-like oxide Ba5In2Al2ZrO3 (a = 5.8707(7) A ̊, a = 24.445(3) A ̊, space group P63/mmc, z = 2) was determined using single crystal data. A least-squares refinement gave conventional and weighted R factors of 0.037 and 0.040 respectively. This structure is a 10L (cchcc)2 sequence of close-packed BaO3 and BaO□2 layers. The main feature of the structure is joint occupation of two 4f positions by In and Al atoms, which result in disordering of oxygen atoms and vacancies in the BaO□2 layers. It was shown that this structure can be considered formally as a result of the intergrowth of Ba2InAlO5-like blocks and BaZrO3 ones along the c-axis of the hexagonal supercell.