Acceptance sampling by exponential smoothing presents a concept whereby each lot is accepted or rejected through interrogation of the current lot and all prior lots submitted. The number of defectives of a lot, in conjunction with historical results, is transformed to a quality index by simple exponential smoothing, utilizing larger values of the smoothing constant to lend more weight to the quality of current lots inspected. This quality index is compared with a predetermined threshold index to determine if the lot is to be accepted or rejected. This quality index is then retained to be used as the historical quality information to be applied to the quality index of the next lot.