The majority of the East Indian immigrants were Hindu, and their dominant sect was Vaishnavite Hinduism. Status differences were attached to castes, and rituals varied with caste status. The higher castes worshipped the classic pantheon of Vishnu and Shiva. Vaishnavite Hinduism remains the predominant religion of the IndoGuyanese , although it has been considerably modified.

During the indenture period, the East Indian caste system, with its reinforced variations of rites and beliefs within the Vishnu cult, broke down. Hinduism was redefined, and caste-distinguishing practices were eliminated. Christian missionaries attempted to convert East Indians during the indenture period, beginning in 1852, but met with little success. The missionaries blamed the Brahmans for their failure: the Brahmans began administering spiritual rites to all Hindus regardless of caste once the Christian missionaries started proselytizing in the villages, hastening the breakdown of the caste system. After the 1930s, Hindu conversions to Christianity slowed because the status of Hinduism had improved and discrimination against Hindus had diminished.

Orthodox Hinduism stresses the festivities accompanying religious rites. Festivals may last several days and are usually held in times of crisis or prosperity. Because the sponsor of a festival provides a tent and feeds a large number of guests, orthodox Hindu rituals require considerable outlays of money. A Hindu family has difficulty fulfilling ritual obligations unless it has accumulated a surplus of cash.

Since the late 1940s, reform movements have caught the attention of many Guyanese Hindus. The most important, the Arya Samaj movement (Aryan Society), was founded in India in 1875 the first Arya Samaj missionary arrived in Guyana in 1910. Arya Samaj doctrine rejects the idea of caste and the exclusive role of Brahmans as religious leaders. The movement preaches monotheism and opposition to the use of images in worship as well as many traditional Hindu rituals.

Data as of January 1992