Laminar natural convection heat transfer from a torus is numerically investigated for two conditions: having an isothermal surface or being uniformly heated. Tori with different diameter ratios are examined under laminar conditions. The computational procedure is based on the finite volume technique. Results are presented in the form of velocity and temperature contour plots around the perimeter of the torus. Heat transfer data are generated and presented in terms of the average Nusselt number versus the modified Rayleigh number. General correlations of Nusselt numbers in terms of a wide range of Rayleigh or modified Rayleigh number are obtained to cover two different heating conditions.