Four diketopiperazine derivatives; cyclo(-Pro-Val) (1), (-)-cyclo(-Pro-Tyr) (2), (-)-cyclo(-Pro-Phe) (3) and (+)-cyclo(-Pro-Leu) (4) were isolated from the ethyl acetate extract of Glaciozyma antarctica PI12, a cold-adapted yeast that belongs to family Kriegeriales. The compounds were isolated by radial chromatography and thin layer chromatography techniques and the chemical structures were elucidated by infrared (IR), ultraviolet (UV), nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry.