The physical aging behavior of nylon 66 as a function of aging temperature, magnitude of applied stress, and aging time has been investigated. Creep tests were performed for samples quenched from a stabilization temperature of 160 degrees C to aging temperatures between 41 degrees C and 65 degrees C, for aging times ranging from 0.5 to 64 h, and at stresses levels from 4 MPa to 24 MPa. Volume recovery was investigated for samples quenched from 160 degrees C to aging temperatures of 41 degrees C and 65 degrees C. The creep compliance curves at different aging times were able to be superimposed. The double logarithmic shift rate was calculated and its dependence on aging temperature and applied stress was determined. Also, it was found that the volume recovery rate depends on the aging temperature. The time-temperature and stress-temperature superpositions were not possible for our data.