As part of a general program to determine the applicability of linear orthotropic theory to the design of cylindrical shells under various loading conditions, a theoretical and experimental investigation was performed on the general instability of orthotropic cylinders under bending and combined axial compression and bending loading. Based on a simple approximation for the asymmetric buckling pattern, theoretical results suitable for design use were obtained for the buckling of orthotropic cylinders for both bending and combined loading conditions. It was shown that the buckling stress for orthotropic cylinders under bending or axial compression loading are equal which agrees with previous results for isotropic cylinders. Theoretical results were evaluated by means of a series of careful experiments performed on orthotropically stiffened cylinders designed to fail in the elastic general instability mode. For both bending loading and the combined axial and bending loading condition, experimental results were in good agreement with the theory. (Author).