Alloys based on the intermetallic phase γ-TiAl are considered good candidates for some high temperature aircraft engine applications. While a tremendous effort has been made to understand the mechanical properties of γ-TiAl, relatively little effort has been made to understand its oxidation behavior. Two of the authors have studied oxidation of several γ-TiAl alloys containing ternary and quaternary additions including Cr, Mn, Nb, Ta, and W. In this paper, we present some of the microstructural observations on an oxidized γ-TiAl alloy.An oxidized γ-TiAl alloy with a nominal composition of 50 at% Al and 2 at% Cr was examined using analytical electron microscopy. Oxidation of polished pieces occurred in air at 850°C for 6 hours. The pieces were ground from the unpolished side to a thickness of ∼75 μm and 3 mm disks were punched. The disks were electropolished in a perchloric/methanol solution. Electropolishing was done from the metal side only until “perforation” of the metal substrate. This resulted in a sample with an oxide ‘window’. The samples were further thinned by ion beam milling (5kV/500μA Ar+) from the oxide surface toward the oxide/metal interface. The sample was examined in a Philips EM430 TEM operated at 300 kV and x-ray spectra collected with an EDAX energy dispersive x-ray spectrometer having a windowless Si(Li) detector.