Five new eriophyoid mites infesting weeds of the family Poaceae are described and illustrated from Egypt. They are Abacarus stagninissp. nov. from Echinochloa stagnina (Retz.) P. Beauv., vagrants in grooves between veins on the upper leaf surface, causing discoloration of the leaves; and four new species from genus Aceria (A. echinochloaesp. nov., A. barnyardisp. nov., and A. stagninissp. nov.) from E. stagnina and E. crus–galli (L.) Beauv., and Aceria pennisetosasp. nov., from Pennisetum purpureum Schumach. These species are vagrants underneath inner surface of the leaf sheath around stem and no symptoms were observed. However, A. barnyardisp. nov. is a vagrant underneath inner surface of the leaf sheath around stem and are endoparasitic inside tissue of leaves causing rusted leaves.