The effect of hole size on sieve tray performance was systematically studied in a 1.22 m distillation column with various tray configurations. The diameters of the sieve holes covered a range from 3.2 to 66.7 mm. The tests were conducted with three different hydrocarbon systems, cyclo-hexane/n-heptane, iso-butane/n-butane, and o/p-xylene at pressures of 0.02 to 27.6 bar. The performance of the sieve trays with different hole sizes was determined and compared. It is found that hole size affects the mass transfer efficiency and capacity. The results also show a significant effect of the hole size on tray pressure drop and weeping. A fundamental analysis is given to explain the effect of hole size on the sieve tray performance.