This paper presents an evaluation of the surface roughness and geometric accuracies in drilling operations performed using U-drills without a pilot hole. The surface roughness, perpendicularity and cylindricity were used as the response parameters for evaluating the effects of the feed rate, peripheral speed, hole diameter and hole depth. The performance characteristics were measured and various signal-noise ratios were calculated with the Taguchi method. An analysis of variance (ANOVA) was performed and the effects of the controlled factors at different levels were analyzed to identify the optimum drilling conditions for U-drills. The results of this study will allow an operator to select the optimum parameter values for U-drills to reduce the manufacturing costs.