Steady, laminar, axisymmetric, and circumferentially uniform flow and heat transfer, including the effects of variable properties and buoyancy, have been modeled within a rotating disk chemical vapor deposition (CVD) reactor. The reactor is oriented vertically, with the hot, isothermal, spinning disk facing upward. The Navier–Stokes and energy equations have been solved for the carrier gas helium. The solutions have been obtained over a range of parameters, which is of importance in CVD applications. The primary parameters are the ratio of the disk temperature to the free stream temperature Tw /T ∞ , the disk Reynolds number Re = r d 2 ω/ν∞ , a mixed convection parameter Gr/Re3/2 = g (ρ∞ − ρw )/(ρw ωων∞), the dimensionless inlet velocity u ∞ /ων∞, and two geometric parameters ro /rd and L/rd . Results are obtained for the velocity and the temperature fields and for the heat flux at the surface of the rotating disk. Comparisons are made with the one-dimensional, variable-property (excluding buoyant effects), infinite rotating disk solutions of Pollard and Newman. Results are presented in terms of a local Nusselt number. The potential uniformity of CVD in this geometry can be inferred from the variation of the Nusselt number over the surface of the rotating disk. The effects of buoyancy and the finite size of the rotating disk within the cylindrical reactor are clearly evident in the present work.