We combine grazing-incidence small-angle X ray scattering (GI-SAXS) with atomic force microscopy (AFM) to determine the surface alignment of thin films of primitive (𝑄 𝐼𝐼 𝑃 ) phase bicontinuous cubic lipid systems. GI-SAXS reveals the 3D symmetry of the nanostructure, to confirm 𝑄 𝐼𝐼 𝑃 phase formation. The positions of spots in the 2D scattering pattern reflect the crystallographic orientation of the unit cell relative to the plane of the substrate, and therefore the facet which terminates the film at the 𝑄 𝐼𝐼 𝑃 phase surface, allowing unambiguous interpretation of the square array imaged by AFM. The orientation was consistent for all three compositions used that formed the 𝑄 𝐼𝐼 𝑃 phase, demonstrating the robustness of the result. These systems comprised of lipid mixtures of monoolein (MO), cholesterol (CHOL) and dioleoylphosphatidylserine (DOPS); and polyoxyethylene surfactant (10) cetyl ether (Brij-56), phytantriol (PHYT) and Cithrol (a commercial version of MO), with additional glycerol for each system for GI-SAXS experiments.