A numerical investigation has been conducted to study the effect of body force on forced-convection of air upward-flow in the thermal entrance region between vertical parallel plates with the constant wall temperature. The governing equations based on the usual Boussinesq approximation are solved for two thermal conditons of parallel plates: one wall cooled with the other wall insulated; and both walls cooled in the same uniform states. The results are discussed in conjunction with those of uniform irrotational velocity. Numerically predicted friction factors and local Nusselt numbers are compared with their counterparts for pure forced convection. For use in practical applications, correlation equations are developed for the friction factors and the local Nusselt numbers.