This study examined the relationships among short-term memory (STM), working memory (WM), and general intelligence (g). Two independent samples of participants performed several verbal, quantitative, and spatial STM and WM tasks, as well as a broad set of tests measuring psychometric intelligence. The constructs are carefully sampled to include heterogeneous tasks and tests to control the effect of unwanted variance. The results have several points of interest. First, there is a strong correlation between STM and WM. Second, WM is a slightly better predictor of g than STM. Third, when the correlation between STM and WM is statistically controlled, the unique predictive power of WM is small, which suggests that the short-term storage component of the WM system largely drives the relationship between WM and g. © 2005 Elsevier Ltd. All rights reserved.