A statistical study of factors affecting the surface finish of parts machined on a five-axis mill was performed. The study was a 23 full factorial experiment. The following factors and levels for each factor were selected: cutter type (flat and filleted end mill), feedrate (12 and 20 inches per minute), and angle of inclination (7 and 15 degrees). All factors were statistically significant. Cutter type was the factor which most significantly affected surface finish, followed by feedrate, and angle of inclination. The effect of cutter type was more than four times greater than the other factors. All two-way interactions were also found to be significant, with the magnitude of the interactions involving cutter type approximately four times greater than the interaction between feedrate and angle of inclination. An acceptable mathematical model for predicting surface finish based on these factors was obtained which can be used in five-axis machining research and applications.