| Posht Asiab | |
| Native Name: | Persian: پشت اسياب |
| Native Name Lang: | fa |
| Settlement Type: | Village |
| Pushpin Map: | Iran |
| Coordinates Footnotes: | [1] |
| Subdivision Type: | Country |
| Subdivision Name: | Iran |
| Subdivision Type1: | Province |
| Subdivision Name1: | Khuzestan |
| Subdivision Type2: | County |
| Subdivision Name2: | Dezpart |
| Subdivision Type3: | District |
| Subdivision Name3: | Central |
| Subdivision Type4: | Rural District |
| Subdivision Name4: | Donbaleh Rud-e Shomali |
| Unit Pref: | Metric |
| Population As Of: | 2016 |
| Population Total: | 384 |
| Population Density Km2: | auto |
| Timezone: | IRST |
| Utc Offset: | +3:30 |
Posht Asiab (Persian: پشت اسياب) is a village in Donbaleh Rud-e Shomali Rural District of the Central District of Dezpart County, Khuzestan province, Iran.
At the time of the 2006 National Census, the village's population was 511 in 99 households, when it was in the former Dehdez District of Izeh County.[2] The following census in 2011 counted 568 people in 122 households.[3] The 2016 census measured the population of the village as 384 people in 85 households. It was the most populous village in its rural district.[4]
In July 2021, the district was separated from the county in the establishment of Dezpart County, which was divided into two districts of two rural districts each, with Dehdez as its capital and only city. The rural district was transferred to the new Central District.[5]