Mucopolysaccharidosis type VI (MPS VI) is a genetic disorder caused by a deficiency of arylsulfatase B (ARSB). In our previous study, we investigated the structural changes in ARSB caused by amino acid substitutions associated with MPS VI, and revealed that such structural changes in ARSB were correlated with the clinical phenotypes. To the best of our knowledge, there is no database containing the structures of mutant ARSBs. Here, we built a database of clinical phenotypes, genotypes and structures of mutant ARSBs (http://mps6-database.org). This database can be accessed via the Internet, and is user friendly being equipped with powerful computational tools. This database will be useful for a better understanding of MPS VI.