The flexural properties of six 150 x 300 x2400 mm concrete beams reinforced with basalt FRP (BFRP) bars were investigated. The beams were divided into two groups , the first group consisted of four beams reinforced with only BFRP bars with reinforcement ratio (ρf) ranged from 3.59 to 8.95 times the balanced ratio (ρfb ) according to ACI 440.1R-06 . The second group consisted of two hybrid beams reinforced with BFRP and steel bars with ρf 3.59 and 5.38 times ρfb in addition to one steel bar of diameter 10mm and yield strength 360 MPa . The beams were tested under four-point bending over a clear span of 2200 mm until failure. The test results of the first group indicated that when ρf increased by 150% , the ultimate deflection was reduced by 50% and ultimate load capacity was increased by 40% compared with the beam that had ( ρf = 3.59 ρfb ) . The mode of failure of the first group beams is concrete crushing in the top compression fiber. The test results of the beams of the second group indicated that adding steel bar of diameter 10mm to the beam that had two BFRP bars (by steel to BFRP reinforcement ratio =35%), led to reducing the ultimate deflection by 42 % while the ultimate load capacity increased by 10%. Moreover , adding steel bar of diameter 10mm to the beam that had three BFRP bars (by steel to BFRP reinforcement ratio =25%), led to reducing the ultimate deflection by 30 % while the ultimate load capacity increased by 8% . This shows that there is a direct relation between steel to BFRP reinforcement ratio and the reduction of deflection and the effect of adding steel bar is more pronounced on reducing ultimate deflection than increasing ultimate load capacity and hence enhancing serviceability of the beams.