A film model is described for free convective heat transfer and friction in the presence of wall suction or injection. The analysis yields a thermal correction factor, which appears to be the classical (Ackermann) expression, and a novel friction correction factor, derived here for the first time. Both correction factors are applied to free convection along a vertical flat porous plate for values of the Prandtl number of 0.73, 1 and 7. Subsequently, the film theory predictions are compared with the numerical and asymptotic results of a boundary layer analysis, performed by previous investigators. On the basis of this comparison, a modified correction factor is proposed which correlates excellently with the results of the boundary layer analyses.