A numerical method has been used to predict the combined convection flow of Newtonian fluids in vertical eccentric annuli, in which the inner and outer walls are held at different temperatures. Assuming that the ratio of the radial to the vertical length scale, e, is small, as found in many industrial applications, then the full steady, momentum, energy, and continuity equations are simplified by expanding the variables in the governing equations in terms of e. The parabolic nature of the simplified equations allows a marching procedure in the vertical direction using a finite difference scheme, and the resulting equations can be solved at each vertical step using the finite element method. Results have been obtained for a range of the governing parameters, namely, the Grashof, Prandtl, and Reynolds numbers.