Summary: Pneumatic conveying of solid materials is used in many process industries where solid particles are carried forward in pipes and channels by the fluid. The pressure drop in the system is dependent on a host of parameters such as particle and pipe diameters, particle and fluid properties, pipe roughness and orientation, etc. In this study, the commercial CFD software, STAR-CD is used to model pneumatic conveying in a horizontal pipe. A range of fluid flow rates is studied. Reasonable agreement is obtained between the predicted pressure drop and the experimental data of R. D. Marcus et al. [Pneumatic conveying of solids. New York, NY: Chapman and Hall (1990)] for spherical particles and N. Vasquez et al. [“Visual analysis of particle bouncing and its effect on pressure drop in dilute phase pneumatic conveying”, Powder Technol. 179, 170–175 (2008)] for non-spherical particles. The sensitivity of the computed results to particle properties and the choice of fluid drag model are also studied.