Expressions for the Ettingshausen figure of merit of bismuth are derived for various orientations on the basis of Abeles and Meiboom's model for the band structure. The calculated values for the maximum figure of merit exceed 5 × 10-3 deg-1 both at 80° K and 300° K. Magnetic fields appreciably greater than 1500 Oe and 25 000 Oe at the respective temperatures would be required. It is shown that improvements by a factor of more than two might be expected using Bi-Sb alloys. Some consideration is given to the possible effect of the presence of a heavy-hole band.