We examine thermal expansion of textured polycrystalline aggregates and focus on polycrystals containing hexagonal monocrystals. Our analysis is based on the coupling of the Voigt–Reuss–Hill averaging procedures for elastic constants, Roe’s [R. J. Roe, J. Appl. Phys.36, 2024 (1965)] framework for the mathematical description of the crystallite orientation‐distribution function (ODF), and the exact connections of Hashin [Z. Hashin, J. Mech. Phys. Solids32, 149 (1984)] and Schulgasser [K. Schulgasser, J. Mech. Phys. Solids35, 35 (1987)] between the thermal‐expansion coefficients of a polycrystalline aggregate and the corresponding polycrystal elastic constants, monocrystal elastic constants, and monocrystal thermal‐expansion coefficients. The results are simple expressions for the polycrystal thermal‐expansion coefficient in terms of the monocrystal elastic constants, thermal‐expansion coefficients, and the coefficients in the expansion of the crystallite ODF in a series of generalized spherical harmonics. We present numerical results for zinc and zirconium polycrystals with textures typical of rolling and extrusion processes. ©1995 American Institute of Physics.