We demonstrate a laser-diode pumped efficient triwavelength laser at about 1.06microm with a Nd-doped yttrium gallium garnet crystal for the first time, to our knowledge. Continuous wave output power of 7.15W was achieved under an absorbed pump power of 14.1W, corresponding to the slope efficiency of 52.7%. With Cr:YAG as the saturable absorber, passive Q-switching performance was obtained. The shortest pulse width, largest pulse energy, and highest peak power were obtained at 3.1ns, 153.8microJ, and 46.6kW, respectively. The laser spectrum was found to be a triwavelength, with respective wavelengths of 1062.1, 1060.3, and 1058.9nm, and three laser transitions were assigned.