A 38-year-old woman with a recurrent suppurative pilonidal cyst was successfully treated causally with an Nd-YAG (neodymium-doped yttrium aluminium garnet) laser, and with no recurrence at 3-month follow-up. A similar success was observed for another 15 consecutively treated patients, including suppurative cases. The effect could be attributable to the ability of the YAG laser to operate at a wavelength of 1064 nm and to penetrate the skin to levels deeper than that of most other lasers before the energy is absorbed in melanin and oxyhaemoglobin. Consequently, the contents of the cyst can be reached and destroyed. The treatment could be a very attractive alternative to open surgery.