The British Picture Vocabulary Scale, second edition (BPVS-II), a measure of receptive vocabulary, is widely used by speech and language therapists and researchers into speech and language disorders, as an indicator of language delay, but it has frequently been suggested that receptive vocabulary may be more associated with socio-economic status. Studies on this topic have produced conflicting results. This study reviews the literature and tests the hypothesis that receptive vocabulary is associated with socio-economic status. The BPVS-II was administered to 76 typically-developing children aged 4 to 11, classified according to deprivation category, in Edinburgh, Scotland. The results showed no significant correlation between the two measures. Error patterns within the results are examined to discover why there should be discrepancy between them and the findings of other studies. The interaction between word frequency and the items used in the BPVS-II is examined, and implications for the use of the BPVS-II with all children of primary school age are discussed.