The successful treatment of furcation-involved multirooted teeth has been a challenge for many clinicians. Furcation lesions have been treated by osseous resection, root amputation, tooth hemisection, and other methods. Recently, guided tissue regeneration has been considered the treatment of choice, but inconsistent treatment outcomes have caused frustration for many clinicians. This article discusses the complexity of the furcation lesion, important aspects of the lesion and its relation to the tooth anatomy, and treatment options that should be considered.