A full factorial experimental design was used to assess the importance of the drilling parameters. Digital photography technique was used to evaluate the damages from drilling. The drilling operation was assessed based on two introduced factors, including the delamination factor (DF) and uncut fiber factor (UCFF). Analysis of the experimental results for DF indicated that feed rate was the most significant parameter. On the other sides, experimental results for UCFF showed that feed rate had the greatest influence. Also, the results revealed that the both factors were increased by the increase of feed rate and there was an optimum point of cutting speed and tool diameter in the evaluation of UCFF. Drilling of balsa wood composite sandwich panel had the best quality followed by corrugated foam and PVC foam sandwich panels.