This chapter concerns the characteristics of short-term memory performance in children with Down's syndrome and other groups of children with severe learning difficulties. Down's syndrome subjects with a group of other subjects of different aetiology, matched for the severity of their learning difficulties. The EPVT raw score was converted into a mental age score using the norm scores from the administrative manual for the test. The original samples of subjects with severe learning difficulties, Down's syndrome and mixed aetiology, were pupils attending local schools for those with severe learning difficulties, or adults who were formerly at the schools. Improvements in Auditory Sequential Memory (ASM) are not significant over two years, but do reach a significant level after five years. However the pace of improvement in Auditory Sequential Memory is very slow, and does not keep up with increases in MA.