This work reports experimental data on the speed of sound in liquid difluoromethane (HFC32, or R32) from T = (248 to 343)K and pressures up to 65 MPa. The results were obtained using a newly-built apparatus, calibrated with toluene over the whole experimental region, and show good agreement with two available data sets. The uncertainties are +/- 0.01 K in the temperature, +/-0.025 MPa in the pressure up to 35 MPa, and +/-0.2 MPa above this value. The final uncertainty on the speed of sound is estimated to be +/-0.2 per cent. The data were fitted using a simple analytical equation and the results are discussed. The isentropic compressibility was calculated over the (p, T) surface where the reported speed of sound values and the corresponding literature densities overlap.