Fungi belonging to the genus Geastrum are known as earth stars due to different layers with specific alignment in fruit bodies. In this paper four species of the genus Geastrum viz. G. coronatum, G. rufescens, G. saccatum and G. schmidelii were reported as new for Iran. Previously reported specimen, G. corollinum (as G. recolligens) was newly collected and was studied in details. Newly reported species were redescribed and illustrated with microphotographs and drawings.