This study was performed to investigate the survival rate of single implant used in maxillary anterior region during follow up periods. 231 patients whose single missing tooth in maxillary region had been replaced with 237 implant at the periodontal dept. of Yonsei University Hospital between February 1993 and December 2004. The following results are compiled from 231 patients who received single implant surgery. 1. The major cause of single tooth loss in maxillary anterior region is trauma, followed by periodontal disease and congenital missing. 2. The total survival rate of single implant placed in maxillary anterior region is 94.5%. 3. The survival rate of single implant placed in type II and type IV was 100% and in type III was 92.7%. As for the bone quantity, the survival rate in type A(100%) was most, followed by type B(97.3%) and type C, D (93.5%). 4. The survival rate of implant placement combined with advanced surgery was 94.4%. The results showed that the placement of single implant is considered as a reliable treatment option for a single missing tooth in maxillary anterior region except in certain extreme conditions especially with poor bone quality and quantity.