The prediction of change in stability upon point mutations in proteins has many applications in protein analysis and engineering. We recently adjoined a new structure-based method called MAESTRO, which is distributed as command line program. We now provide access to the most important features of MAESTRO by an easy to use web service. MAESTROweb allows the prediction of change in stability for user-defined mutations, provides a scan functionality for the most (de)stabilizing n-point mutations for a maximum of n = 5, creates mutation sensitivity profiles and evaluates potential disulfide bonds. MAESTROweb operates on monomers, multimers and biological assemblies as defined by PDB.