There is little research on language involvement in MS, though the studies that do exist indicate a wide variety of language impairments. No comprehensive study has yet been done investigating MS abilities in all the major language domains. This study used one receptive and one expressive test for each of syntax, semantics, phonology and written language to assess patterns in MS language skills. The results of the group analysis indicate that MS patients are significantly impaired in receptive syntax, word-finding, reading, non-word repetition and spelling. The patients were then divided according to MS subtype. Analysis by subtype revealed that secondary progressive patients are linguistically preserved compared to primary progressive and relapsing-remitting groups on reading, and compared to the primary progressive group on word-finding. An individual analysis showed that subsets of individuals are significantly impaired on most of the language tests used. Syntax was impaired in exactly half of each subset, and double dissociations were seen between syntax and semantics. One case study is also reported: a woman with a suspicion of MS in her medical history and poor performance on the language tests.