An inverse boundary analysis of surface radiation in an axisymmetric cylindrical enclosure is conducted in this study. The net energy exchange method was used to calculate the radiative heat flux on each surface, and a hybrid genetic algorithm was adopted to minimize an objective function, which is expressed by the sum of square errors between estimated and measured or desired heat fluxes on the design surface. We have examined the effects on the estimation accuracy of the measurement error as well as the number of measurement points. Furthermore, the effect of a variation in one boundary condition on the other boundary conditions is also investigated to get the same desired heat flux and temperature distribution on the design surface.