Abstract: The Siwalik formations of northern Pakistan consist of (fluvial) deposits of ancient rivers that were formed from the early Miocene up to the late Pliocene. The tertiary continental deposits of the Siwaliks are highly fossiliferous with a diverse array of terrestrial and freshwater vertebrates in which ruminants are fairly abundant. The rich Siwalik fossil record presents a detailed history of the prehistoric mammals of the Indian Subcontinent. In this research it was analyzed individual well-sampled sites to study the past ruminant community. The Siwalik fossil record becomes increasingly informative for diverse research questions in paleobiology as a result of its growing and robust data set. The fossils from Pakistan may also document the first appearance and subsequent radiation of giraffes and bovids, two groups that dominate the late neogene (tertiary) as well as the modern herbivore faunas. Throughout the Siwalik formations, the ruminants are by far the most abundant mammal group. The number of ruminant species, as recorded in the tertiary hills of the Siwaliks is clearly greater than that observed in most ecosystems today, which probably indicates overall greater species richness than is typically present. Today, the ruminants constitute the largest group of ungulates, with more than 190 species and its distribution is widespread in all continents except Australia and Antarctica.