The present invention relates to a rubber modified thermoplastic resin composition comprising a discontinuous elastomeric phase dispersed in a rigid thermoplastic phase, wherein at least a portion of the rigid thermoplastic phase is grafted to the elastomeric phase, which is prepared by a method comprising the steps of: (a) polymerizing a mixture of monomers in a first stage in the presence of the elastomeric phase, at least one of which monomers is selected from the group consisting of vinyl aromatic monomers and at least one of which monomers is selected from the group consisting of monoethylenically unsaturated nitrile monomers, followed by (b) polymerizing one or more monomers in at least one subsequent stage in the presence of the elastomeric phase from (a), wherein the one or more monomers comprise at least one monomer selected from the group consisting of (C1-C12)alkyl- and aryl-(meth)acrylate monomers. The method is also provided.