Bicrystals of a Cu–2.0 wt.% Sb alloy with different [0 0 1] symmetric tilt boundaries were tensile tested at several temperatures from 77 to 743 K. The dependence of Sb segregation level at [0 0 1] tilt boundaries on the misorientation angle also was examined by energy-dispersive X-ray spectroscopy. The fracture behavior was sensitive to the misorientation angle and test temperature. Both the fracture behavior at 77 K and the Sb segregation level showed a good correlation with the grain-boundary energy of pure Cu. The higher the grain-boundary energy, the higher the Sb segregation level and the higher the degree of grain-boundary embrittlement