We demonstrated diode-pumped CW and passively Q-switched Nd:YVO 4 laser using an ultra-thin (100 μm) crystal as the gain medium. The experiments showed that the laser can keep operating in single transverse mode with a very narrow output spectrum even when the incident pump power increased to several ten times above the threshold. Using the same linear plano-concave cavity, we realized stable passively Q-switched Nd:YVO 4 laser by inserting a Cr 4 + :YAG crystal into the cavity. Contrast to these, diode-pumped normal Nd:YVO 4 laser using thick (e.g. 1 mm) crystal as the gain medium often operates in multiple modes and is difficult to realize Cr 4 + :YAG passively Q-switched laser in such a cavity.