The Gorgan Plain (NE Iran) is largely treeless today but it possibly was not in the past. We use palaeobotanical data from radiocarbon-dated sediments and archaeological excavations to investigate the extent and use of woodland under the Sasanian Empire (224–651 CE). Palynology, anatomical studies of charred and uncharred wood, insects and botanical macroremains have shed new light on this question. Palynological research points to natural origins of the open steppe vegetation in the Gorgan Plain contrasting to carpological and wood anatomy studies indicating wide use of trees and shrubs during the Sasanian period. As it shown by charcoal data, local sources provided enough firewood for kilns in short-term use, but were insufficient for supplying fortification garrisons which required additional supplies from the Hyrcanian forests. These forests provided the main source of firewood for sites located close to the Alborz Mountains. Cultivation of trees was widespread during the Sasanian era for fruits, shadow and possibly moriculture for silk production. Palaeobotanical records are still very rare in the Gorgan Plain. New data are a desideratum to gain further insights into woodland use before, during and after the Sasanian Empire.