Reinforcement of unsaturated polyester by particulates plays is an important role in the improvement of the mechanical properties of high performance materials. Hence, the mechanical behavior of recycled (grapes and dates) particulate polyester composites was studied in order to develop an engineering material for industrial applications. Different percentages (0, 1.5, 3.5 and 5)% of the reinforcement Particles were added to unsaturated polyester resin. Numbers of mechanical tests were included (thermal conductivity test, hardness test, Dielectric testing, tensile test, impact test). The results showed that the hardness and dielectric constant of filled unsaturated polyester increase with the increment of the percentage of grapes and dates particles, while impact resistance decreases. On the other hand the thermal conductivity increase at (1.5%) of percentages and decreases of (3.5%, 5%) of grapes particles while the value of thermal conductivity decrease by (1.5%) and increased when increasing (3.5%, 5%) of the dates particle. The tensile strength improves of grapes reinforcing particles and increase with an increase in the particle percentage of grapes and the value of tensile strength increases with the dates particle content (1.5%). Also that the percentage of (3.5%) represents the greatest value for the modulus of elasticity for unsaturated polyester reinforced with dates particle and the percentage of (5%) represents the greatest value for the modulus of elasticity for unsaturated polyester reinforced with grapes particle.