A new simplified model to describe light scattering in heterogeneous photocatalytic reactors has been developed using a radiative transport equation. To obtain a solution to the complex integrodifferential equation describing light intensity distribution, the integrand representing the in-scattering contribution was solved by assuming that the reactor space could be partitioned into finite hexagonal elements to permit reception of incident radiation in six directions (from six neighboring hexagons). Combining this in-scattering component with the solution of the Lambert form of the general equation provided the complete light distribution profile within the reactor. Three phase-function parameters were used to define forward, isotropic, and backward scattering scenarios. The model predictions compared well (error < 8%) with the experimental data.