Both Low Intensity Pulsed UltraSound (LIPUS) and low level heat have separately been shown to improve mineralization in bone cell cultures (Unsworth et al 2007, Leon et al 1993). This study examines the effect of concurrent LIPUS and low level heat on MC3T3-E1 bone cell cultures. The treatment groups were: LIPUS, heat, LIPUS + heat, and control. The LIPUS intensity was ISATA=10 mW/cm2 at f=1.5 MHz, and heat was applied at 40ºC for 40 minutes each day over 15 days. The LIPUS + heat group received the treatments concurrently. The groups were compared using Alizarin Red staining to measure the degree of cell mineralization. All treatment groups showed statistically significantly improved mineralization over the control; however, there was no statistical difference between the LIPUS and the LIPUS + heat groups. Early results suggest that concurrent heat and LIPUS on MC3T3-E1 bone cells has no additive effect on mineralization.