The behavior of adenoid cystic carcinoma (ACC) of the salivary glands has been shown to be unpredictable in terms of local and distant spread and mortality. We retrospectively studied 35 operations in 34 patients who had had a pathologic diagnosis of ACC of the salivary glands and who had been treated over a 20-year period and followed for a minimum of 10 years. We analyzed the effect that different factors had on outcomes. The site of origin appeared to be an important factor in survival rates; survival among patients with tumors that had originated in the parotid gland was fairly good, while survival among those with tumors that originated in the minor salivary glands was significantly worse. TNM staging was another significant factor in survival. Other poor prognostic indicators were local spread, nodal positivity, distant metastasis, and local and regional recurrence. Radiation and chemotherapy did not appear to be beneficial for patients with advanced disease. We recommend radical surgery with complete resection for all patients with ACC of the salivary glands and a careful assessment of the neck in patients with minor salivary gland tumors.