Objectives: To determine the prevalence of the hard and soft tissue lesions biopsied in the Department of Oral Surgery of the Barcelona University Dental Clinic (Barcelona, Spain). Study design: A retrospective descriptive study was made of the biopsies performed between January 2007 and April 2009 in our Department of Oral Surgery. The following variables were recorded: age, the sex, location of the lesion, the biopsy technique, the reason for consultation, and the histological result obtained. Results: A total of 460 lesions amenable to histological analysis and corresponding to 450 patients were analyzed. The most frequently biopsied lesions were maxillary cysts, including particularly root cysts (20%). Other very common disorders in our series were epithelial hyperplasias (10.6%) and fibromas (10%). There was a broad range of histopathological results, with un total of 36 different diagnoses. Three of the 460 biopsies yielded two squamous cell carcinomas and one ameloblastoma. Conclusions: The most prevalent hard tissue lesions were chronic maxillary periapical lesions, while epithelial hyperplasias and fibromas were the most frequent soft tissue lesions. Emphasis is placed on the need for biopsy particularly for studying premalignant and malignant lesions, in view of the importance of securing an early diagnosis.