Recently, Just-In-Time (JIT) purchasing practices have been recognized as a cornerstone of Japan's success in improving product quality and productivity. Traditionally, however, US firms have treated purchasing functions as a ‘profit centre’. This paper presents the proposition that US firms must recognize the potential of purchasing activities as ‘quality and productivity centres’ through successful implementation of JIT purchasing. Personal interviews have been conducted at four US manufacturing firms in an effort, first, to identify the major activities of JIT purchasing that have favourable effects on product quality and productivity and, second, to describe how these activities can improve product quality and productivity in US firms.