Tidal stream turbines provide a predictable and sustainable source of energy. They can be sized to suit the requirements of the local environment, and can be placed in either an individual or ‘farm’ configuration. The work described in this paper provides CFD validation data from a series of laboratory tests undertaken on a scaled model of a horizontal axial tidal turbine (HATT). The laboratory tests used a 0.5 m diameter three bladed turbine in a water flume which had a uniform flow profile with a magnitude of 1 m/s (~2 knots). Experimental data for power and torque were generated using a Baldor servomotor, load and control system. The motor’s speed and torque were controlled and logged. The power and torque data are compared to that produced from a series of CFD models of the same turbine, rotating over the full range of angular velocities with the flume boundary conditions, using the software package FLUENT. The comparative study shows that the CFD models provide excellent predictions of power and torque.