The number of the Mahapuranas, the sacred text was eighteen. But the expansion of purana literature went on unabated. For this reasons those of the puranas, which did not find a place in the traditionally listed Puranas, were conciliated under the title `Upapuranas`. The incongruity in this regard is that in due course of time the numbers of these Upapuranas were also got fixed at eighteen. They were considered as supplementary material that is collected and appended at the back of a book to the Mahapuranas and hence of lesser importance.

Puranas usually are categorized into a Maha and an Upa. Maha`s are regarded as `great` and the Upa`s are lower or additional. The Upapuranas like other puranas narrate on five themes called pancalaksana, which means "five distinguishing marks". All most three Upapuranas deal with that five distinguishing marks named as pancalaksana. Puranas use a large quantity of religious and philosophical concepts from Bhakti to Samkhya, in their narration. The lists of these Upapuranas, as given in the various Mahapuranas do not tally. Quantity is less clearly defined in the Upapuranas and these are also not been critically edited.

The puranas are mainly available in colloquial speech translations. Some Upapuranas to be named are Sanat-kumara, Narasimha, Brihan-naradiya, Siva-rahasya, Durvasa, Kapila, Vamana, Bhargava, Varuna, Kalika, Nandi, Surya, Parasara, Vasishtha, Devi-Bhagavata, Ganesa, Mudgala and Hamsa. Among these the Ganesa and Mudgala Puranas are sectarian Upapuranas devoted to Ganesha. The Devi Bhagavata Purana glorify the chastities of the goddess Durga as the supreme being. Along with the Mahatmya of the Markandeya Purana, Devi Bhagavata Purana has become a basic text for Devi worshipers.

Though the Upapuranas are more sectarian in disposition concerned in propagating their own cults but the general content of these Upapuranas is indistinguishable with those of the Mahapuranas.