CFD simulations of a two-dimensional steady state flow past a rotating circular grooved cylinder is analyzed in this study. Cylinder of diameter 0.1 m with 8 grooves of 0.01 m was examined at various Reynolds’s number (0.1 to 50) and angular velocity (0 to 100 RPS). Incompressible Navier Stokes equation in Ansys Fluent 14.0 was used to examine the flow. The pressure and velocity contours for various Reynolds’s number were generated. The result suggested that the flow remains attached to the surface of the cylinder up to the Reynolds number value of 4–5 and the flow pattern was independent of angular velocity at Reynolds’s number 45-46 and the cylinder behaved like a stationary cylinder and above these Reynolds’s numbers the flow is still two-dimensional, but no longer steady.