The present study was undertaken to investigate the changes induced by chilling on fatty acid composition of tonoplast vesicles from hypocotyls of Vigna unguiculata (L.) Walp. The 7 day-old control seedlings were grown at 25°C while treated seedlings were submitted to low temperatures (10°C and 4°C) for 4 days after 3 days germination. The chilling stress resulted in a differential inhibition of plant growth at 10°C and 4°C. Following chilling at 10°C and 4°C, the rate of unsaturated to saturated fatty acids increased under chilling stress. Our results suggest that the increase of unsaturated fatty acids content as well as the higher rate unsaturated/saturate fatty acidsmight be used by V. unguiculata plants as an adaptation mechanism likely to maintain the vacuolar membrane fluidity under low temperatures.