The Pahlavas are a people mentioned in ancient Indian texts like the Manu Smriti, various Puranas, the Ramayana, the Mahabharata, and the Brihat Samhita. According to P. Carnegy, In the 4th century BCE, Vartika of Katyayana mentions the Sakah-Parthavah demonstrating an awareness of these Saka-Parthians, probably by way of commerce.
Pahlavas are referenced in various Puranic texts like Vayu Purana, Brahmanda Purana, Markendeya Purana, Matsya Purana, Vamana Purana etc.
Kirfel's list of Uttarapatha countries of the Bhuvanakosha locates the Pahlavas along with the Tusharas, Chinas, Angalaukikas, Barbaras, Kambojas, Daradas, Bahlikas and other countries of the Udichya division of ancient India. e.g.:
ete desha udichyastu
Kambojashchaiva Dardashchaiva Barbarashcha Angaukikah ||
Chinashchaiva Tusharashcha Pahlavadhayata narah ||.
The Vayu Purana, Brahamanda Purana and several other Puranas mention the Pahlavas with the tribes of Uttarapatha or north-west. The 6th century CE text Markendeya Purana lists the Pahlavas, Kambojas, Daradas, Bahlikas, Barbaras, Tusharas, Paradas, Chinas, Lampakas etc. as the countries of Udichya division i.e. Uttarapatha, but 58th chapter of the Markendeya Purana also refers to yet other settlements of the Pahlavas and the Kambojas and locates them both specifically in the south-west of India as neighbors to the Sindhu, Sauvira and Anarta (north Saurashtra) countries. Further the 6th century Brhatsamhita of Varaha Mihira also locates the Pahlavas and Kamboja kingdoms in south-west India i.e. around Gujarat/Saurashtra.
Puranas like Vayu also state that the Udichyas including the Pahlavas, Paradas, Gandharas, Sakas, Yavanas, Tusharas, Kambojas, Khasas, Lampakas, Madhyadesis, Vindhyas, Aprantas, Dakshinatyas, Dravidas, Pulindas, Simhalas etc. would be proceeded against and annihilated by Kalki in Kali Yuga. And they are stated to have been annihilated by king Pramiti at the end of Kali age as per Puranic evidence.
According to Vayu Purana and Matsya Purana, river Chakshu (Oxus or Amu Darya) flowed through the countries of Pahlavas, Tusharas, Lampakas, Paradas and the Sakas etc.