An analysis is made to determine the heat transfer characteristics for laminar flow of a heat generating fluid in a circular tube with wall heat transfer. The internal heat generation is permitted to vary in an arbitrary manner both longitudinally along the tube and radially across the section. In addition, arbitrary longitudinal variations in the wall heat transfer may be present. The results obtained apply along the entire length of the tube, that is, in the thermal entrance region as well as far down the tube. Numerical results are evaluated for certain special cases such as uniform and parabolic radial heat source distributions.