We present a battery of four working memory tasks that are implemented using MATLAB and the free Psychophysics Toolbox. The package includes preprocessing scripts in R and SPSS to facilitate data analysis. The four tasks consist of a sentence-span task, an operation-span task, a spatial short-term memory test, and a memory updating task. These tasks were chosen in order to provide a heterogeneous set of measures of working memory capacity, thus reducing method variance and tapping into two content domains of working memory (verbal, including numerical, vs. spatial) and two of its functional aspects (storage in the context of processing and relational integration). The task battery was validated in three experiments conducted in two languages (English and Chinese), involving more than 350 participants. In all cases, the tasks were found to load on a single latent variable. In a further experiment, the latent working memory variable was found to correlate highly but not perfectly with performance on Raven's matrices test of fluid intelligence. We suggest that the battery constitutes a versatile tool to assess working memory capacity with either English- or Chinese-speaking participants. The battery can be downloaded from www.cogsciwa.com ("Software" button).