The Geirud Formation, west of Garmabdar, northeast of Tehran, overlies with obvious disconformity the Mila Formation. Moderately diverse and reasonably well–preserved palynofloras occur in the study material collected from this rock unit. Miospores and acritarchs quantitatively dominate the palynofloras recovered. Palynomorphs with known vertical ranges, namely, Geminospora lemurata, Unellium lunatum, Tornacia sarjeantii, Chomotriletes vedugensis, Cymatiosphaera perimembrana, and Daillydium pentaster suggest a Late Devonian age; thus corroborating the previous palaeozoological-based (Goniatites and Fish) dating. The co-occurrence of marine microphytoplankton cysts (acritarchs & prasinophyte phycomata) with abundant palynomorphs of terrestrial derivation implies a shallow, nearshore marine depositional setting. In the palynofloras investigated, presence of Geminospora lemurata associated with various representatives of Verrucosisporites & Ancyrospora indicates that progymnosperms and fern allies were among major components of plant community existing around the Geirud Formation depositional environment.