Seventy two cases of selection error of upper anterior artificial teeth due to the esthetic factors were investigated out of the 1,507 cases of removable dentures, which were made at the Prosthodontics department of Nihon University school of dentistry at Matsudo for 17 years from November, 1971 to November, 1988. The following were the results of the investigation. 1. Frequency of the selection errors amounted to 4.8% of the total selected cases as broken down in 1.6% by Shade and 4.0% by Mould, the rate of selection errors of the Mould being significantly high. 2. By Mould, selection errors in Ovoid type occupied a significantly high rate. 3. Regarding frequency of Mould after re-selection ST and TO occupied a high rate of 45.9%. 4. Mould of re-selection were almost uniformly small, showing a trend of intumescence becoming emphatically.