We compare the effectiveness of various known Organometallic transesterification catalysts with a novel SnCl2 center dot 2H(2)O transesterification catalyst in the formation of homogeneous PC/PMMA blends with single T-g. It is shown that SnCl2 center dot 2H(2)O works more efficiently than the other organometallic transesterification catalysts. Even 0.1% (wt/wt) of SnCl2 center dot 2H(2)O is enough to establish an interaction between PC and PMMA phases, leading to the formation of a homogeneous PC/PMMA blend with single T-g and single degradation temperature. FTIR, H-1 NMR, and XRD studies provide evidence of the formation of PC-g-PMMA graft copolymer, which acts as a compatibilizer between the PC and PMMA phases. A significant improvement in the optical transparency of the PC/10PMMA blend prepared using SnCl2 center dot 2H(2)O catalyst as compared with PC/10PMMA without any catalyst is observed. There is also a change in the morphology from granular in uncompatibilized blends to lamellar in the compatibilized blends.