Synchronous ipsilateral tumor formation within a major salivary gland is a very rare event. In this case, a 54-year-old female tobacco smoker presented with a slowly enlarging left parotid gland. Computed tomography of the neck demonstrated a solid mass superficial to a cystic mass in the deep lobe of the gland. Ultrasound-guided fine needle aspiration yielded oncocytic cells, lymphoid cells, and granular debris along with rare cohesive groups of basaloid cells. Parotidectomy was performed, and the resected gland was found to contain two adjacent but distinct masses. One mass, a predominantly solid, well-circumscribed lesion composed of ribbons of double-layered oncocytic cells and a lymphoid stroma with germinal center formation, was a Warthin tumor. The other mass, a predominantly cystic lesion composed of cords and nests of basaloid cells with associated deposits of basement membrane-like material, was a basal cell adenoma of the membranous type. To our knowledge, this is the first reported case of synchronous Warthin tumor and basal cell adenoma of the parotid gland with cytologic-histologic correlation attributable to each tumor.