The results of using reed fiber as a fibrous filler for foam concrete are presented. Thus, the workability of a concrete mixture decreases as the amount of fiber increases from 0 to 2%. In the range of fiber content from 2 to 4%, workability increases slightly, after which (at a fiber dosage of 4 to 6%) it decreases again. The maximum compressive and flexural strengths are achieved by adding 3% reed fiber and are 27.96 and 2.16 MPa, respectively. The optimal dosage of reed fiber is 2…3%. Thus, reed fiber is an effective fibrous filler for foam concrete.