At our institutions, most cases of the solid or multicystic type were treated as conservatively as possible in order to avoid disadvantages of radical treatment. The aim of present study was to retrospectively analyze the ameloblastoma cases diagnosed at our two institutions, to classify them according to the criteria of the 2005 WHO classification, and to evaluate the possibility of using a conservative approach for the surgical treatment of ameloblastoma. Maxillary cases, unicystic cases, peripheral cases and resection-treated cases were excluded from this study. In 23 tumors of mandibular solid or multicystic ameloblastoma, a patient's age, gender, location, clinical signs, duration, radiographic appearance, preoperative diagnosis, ameloblastoma subtypes, treatment, and recurrence were investigated. The recurrence rate (48.7%) in this study was lower than the reported recurrence rate after conservative treatment for solid or multicystic ameloblastoma and was higher than the reported recurrence rate of ameloblastoma, inclusive of other types. However, all patients who were diagnosed with recurrences have maintained their quality of life and were satisfied for at least several years after the conservative treatment. In conclusion, we demonstrated one possibility that a conservative approach might be employed in the surgical treatment of ameloblastoma (even of the solid or multicystic type).