This paper reviews theoretical and methodological issues in the measurement of drug craving, with an emphasis on self-report assessment. Despite the important role that craving plays in many research and clinical settings, the way in which the construct is conceptualized and measured rarely receives sufficient attention. Issues pertinent to conceptualizing craving are identified. Because there is no single perfect measure of craving, it is essential that researchers understand the limitations of each measure. Measurement performance concerns that affect the validity of different measures are reviewed. Non-verbal assessment methods are also reviewed. Research factors that may help determine the optimal measures for a given study are highlighted. It is concluded that advances in assessment will proceed only when combined with additional research and a better theoretical understanding of craving.