This article offers a short review of risk factors, oral precancerous conditions, and oral precancerous lesions which may cause oral squamous carcinoma. Current diagnostic methods and multidisciplinary strategies for the early detection and appropriate therapy of oral squamous carcinomas are discussed. Close cooperation of oral and maxillofacial surgeons, head and neck surgeons, radiotherapists, and oncologists is essential for the effective therapy of oral squamous carcinomas.