Qazqan Darreh () is a village in Dibaj Rural District of Lotfabad District in Dargaz County, Razavi Khorasan province, Iran.
At the time of the 2006 National Census, the village's population was 343 in 57 households. The following census in 2011 counted 476 people in 113 households. The 2016 census measured the population of the village as 522 people in 142 households.