Experimental tests on cylindrical specimens have underlined the effectiveness of FRP-based confinement systems; tests conducted on cubic samples have also pointed out the reduction of the confinement effectiveness due to the high stress concentration in the corners; it has been observed that such effect becomes lower as the corner radius increases (i.e., cubic tends to cylindrical). Along with experimental work, some researchers have attempted to develop numerical models able to predict the behavior of FRP confined concrete. The present paper focuses on the behavior of RC members subjected to axial load plus bending and confined by composite materials. It presents a model that allows computing the flexural capacity of such elements and evaluating the moment curvature curve for a given square or rectangular cross section under a fixed axial load. The analytical results are compared to experimental data obtained by tests on RC columns confined with steel hoops and FRP.