He studied natural sciences at various universities in early modern Germany and worked primarily in the Russian Empire between 1767 and 1810.

Pallas wrote Miscellanea Zoologica (1766), which included descriptions of several vertebrates new to science which he had discovered in the Dutch museum collections.

In 1767, Pallas was invited by Catherine II of Russia to become a professor at the St Petersburg Academy of Sciences and, between 1768 and 1774, he led an expedition to central Russian provinces, Povolzhye, Urals, West Siberia, Altay, and Transbaikal, collecting natural history specimens for the academy.

He explored the Caspian Sea, the Ural and Altai Mountains, and the upper Amur River, reaching as far eastward as Lake Baikal.

The regular reports which Pallas sent to St Petersburg were collected and published as Reise durch verschiedene Provinzen des Russischen Reichs ("Journey through various provinces of the Russian Empire", 3 vols., 1771–1776).

They covered a wide range of topics, including geology and mineralogy, ethnographic reports on the native Eurasian peoples and their indigenous religions, and descriptions of new plants and animals.

Pallas settled in St Petersburg, becoming a favourite of Catherine II and teaching natural history to the Grand Dukes Alexander and Constantine.

The Empress bought Pallas's large natural history collection for 2,000 rubles, 500 more than his asking price, and allowed him to keep them for life.

Pallas spent early 1794 exploring to the southeast, and in July travelled up the valley of the Dnieper, arriving back in St Petersburg in September.