The article presents the results of studies of the physical and mechanical properties of gypsum concrete with organic filler, which were considered sawdust and flax shreds. It has been shown that the introduction of organic fillers into gypsum concrete leads to a decrease in strength indicators, density, softening coefficient, and an increase in porosity and water absorption. It is noted that the properties of gypsum concrete with sawdust and flax fire are different. With the same amount of organic fillers in the composition of gypsum concrete, flax fire gives a greater reduction in strength, density, softening coefficient and porosity. Flax burning does not change the mobility of the original gypsum concrete mixture and does not affect the water absorption of gypsum concrete. Gypsum concrete with flax kernels loses moisture faster when hardening in air-dry conditions, which will reduce energy costs for drying products. It has been shown that the efficiency of using organic aggregates in gypsum concrete can be increased when used in conjunction with glass fiber.