Arasanj-e Qadim (Persian: اراسنج قديم)[a] is a village in Zahray-ye Pain Rural District of the Central District of Buin Zahra County, Qazvin province, Iran.

At the time of the 2006 National Census, the village's population was 670 in 139 households.

[5] The 2016 census measured the population of the village as 3,740 people in 1,061 households.

It was the most populous village in its rural district.

This Buin Zahra County location article is a stub.