The aim of the present study was to investigate the reliability and validity of a brief standardized assessment of children’s working memory; Lucid Recall. Although there are many established assessments of working memory, Lucid Recall is fully automated and can therefore be administered in a group setting. It is therefore ideally suited to large-scale screening or research purposes. The findings indicated suitable test–retest reliability. Scores were also correlated with children’s scores on the Wechsler Intelligence Scale for Children–IV working memory subtests, scholastic attainment, and ratings of children’s working memory behaviors. Working memory scores also distinguished between children with and without special educational needs. The findings are discussed in terms of practical implications for practitioners.