A compact, diode-pumped passively Q-switched Nd3+:Gd3Ga5O12 (Nd:GGG) laser with Cr4+:YAG saturable absorber has been successfully demonstrated. Stable Q-switched pulses with pulse energy of 100 μJ and high peak power of 14 kW have been obtained. The pulse width was as short as 7 ns with low repetition rate of 10 kHz. The dependence of pulse width, pulse repetition rate, pulse energy and pulse peak power on pump power have been measured respectively. Experimental results reveal that the Nd:GGG crystal with Cr4+:YAG saturable absorber is suitable for narrow pulse width and high power passively Q-switched lasers.