We demonstrate a passively Q-switched Er,Yb:GdAl3(BO3)(4) diode-pumped laser emitting near 1.5 mu m. By using a single-walled carbon nanotube (SWCNT) as a saturable absorber, Q-switched laser pulses with energy of 0.8 mu J and duration of 130 ns at a maximum repetition rate of 500 kHz were obtained at 1550 nm.