When a metal culvert is buried under a railway or road embankment, large compressive thrusts can develop in the structure as a result of loads from traffic and from the embankment itself. Culverts are liable to elastic buckling failure, because their flexural stiffness is usually low. This technical note reports a study, whose objectives are to: (1) investigate the elastic stability of elliptical tubes: (2) extend the parametric solution, already available for cylindrical tubes, to the behaviour of elliptical tubes. Using a linear finite element analysis for flexible culvert buckling, it is found that the linear buckling strength of an elliptical tube is approximated well by that of a circular tube of the same circumference. Published results for circular tubes buried near the ground surface can also be used for shallow buried elliptical tubes having the same ratio of cover depth to half-span. For non-uniformly loaded circular tubes, maximum hoop force can be used to calculate a conservative factor of safety relative to the critical hoop force for uniformly stressed structures. Both experimental and theoretical researches support the finding that linear buckling is a useful estimate of metal culvert elastic buckling strength. (Author/TRRL)