Melting of cubic boron arsenide, BAs, has been studied at pressures up to 8 GPa using in situ electrical resistivity measurements. It was found that above 2.5 GPa BAs melts congruently, and the melting curve has a negative slope (-53+/-5 K/GPa), indicating a higher density of the melt as compared to the solid phase. The melting point of BAs at ambient pressure has been estimated to be 2410(30) K.