The surface tensions of trans-1,3,3,3-tetrafluoropropene (HFO-1234ze(E)) alone and when mixed with difluoromethane (HFC-32) were measured using the differential capillary-rise method. Twenty-three data points for HFO-1234ze(E) were obtained in the temperature range 273-333 K. Twenty-six data points for the 50.00 mass% HFO-1234ze(E)+50.00 mass% HFC-32 mixture were obtained in the temperature range from 273-323 K. The experimental uncertainty of the surface tension was estimated to be 0.2 mN m(-1) for pure HFO-1234ze(E) and 0.3 mN m(-1) for the fluid mixture. Based on the obtained data, the surface tension correlations for HFO-1234ze(E) and the HFO-1234ze(E)+HFC-32 mixture were formulated. The correlations can represent the data with a standard deviation of 0.06 mN m(-1) for HFO-1234ze(E) and 0.18 mN m(-1) for the HFO-1234ze(E)+HFC-32 mixture.