Lord Siva is the primary deity of the temple, represented in the form of a Lingam, symbolizing the concept of God as both with form and formless. As one of the principal deities in the Hindu trinity, Lord Siva holds a prominent place in Hindu temples and is especially revered by Tamil Hindu devotees. Although he is depicted as the Lingam in the main sanctum, he has taken many other forms to inspire devotion and adoration.
As Dakshinamurthy, Lord Siva appears as a teacher to seven Rishis (saints). In the form of Arthanareeswarar, he is depicted as both Parvathi Amman and Lord Siva in one body, symbolizing the complementary nature of the genders in life. He is also portrayed as Nataraja, the Lord of the cosmic dance, reminding devotees of the eternal cycle of creation, preservation, and dissolution, which he governs through his dance.
The Lingam installed in the temple is unique, as it was not man-made. It was discovered in the sacred waters of the Ganges near Kasi (Varanasi) and was kept in continuous worship before being installed in the temple. This Sivalingam is naturally formed, known as Vidankeeswarar, and is the largest of its kind in North America. The deity here is named Vaidyanatha Swamy.