The effect of heat setting and subsequent dyeing on the mechanical properties of poly(lactic acid)(PLA) fabrics was investigated, including the amount of pilling and "Year resistance. The PLA fabric exhibits significantly reduced tear strength as well as pilling and wear resistance as the heat setting temperature and time increase. While the tensile strength decreased above a setting temperature of $120^{circ}C$, surprisingly the tensile strength of the set PLA fabric did increase slightly as the setting temperature was increased to values below $120^{circ}C$, After dyeing, the other mechanical properties, pilling, and wear resistance of the PLA fabrics exhibited similar behaviors to the heat setting treatment. From these results, the heat treatment conditions of PLA fabric should be carefully decided to avoid the deteriorating effects on PLA fabrics.