The aim of the present study was to investigate the potential of the Working Memory Rating Scale (WMRS), an observer-based rating scale that reflects behavioral difficulties of children with poor working memory. The findings indicate good internal reliability and adequate psychometric properties for use as a screening tool by teachers. Higher (i.e., more problematic) teacher ratings on the WMRS were associated with lower memory scores on direct assessments of working memory skills, as measured by the Automated Working Memory Assessment (AWMA) and the WISC-IV Working Memory Index. The use of the WMRS will allow educators to draw on their expertise in the classroom for early detection of children with working memory failures. (Contains 1 figure and 1 table.)