Retinoblastoma is a malignant tumor of the retina which most often occurs in children below 5 years of age with an incident rate of about 1 in 15,000 to 18,000 live births. Retinoblastoma is the first ever cancer that was reported to have a genetic basis. It occurs widely due to inactivating mutations in RB1 gene. Gene expression studies, copy number variation analysis, epigenetic profiling including miRNA and methylation of retinoblastoma has been carried to understand the disease mechanism and key players in the disease. Our group has earlier performed differential proteomics of retinoblastoma to identify proteins of therapeutic importance. However, there are no studies to understand the signalling mechanisms associated with retinoblastoma. Hence, global phosphoproteomics of retinoblastoma was carried out to identify signalling events associated with this cancer. Our study identified stress response proteins to be hyper phosphorylated which included H2AFX and sirtuin 1. In particular, Ser140 of H2AFX also known as gamma-H2AX was found to be hyperphosphorylated in retinoblastoma that indicated activation of DNA damage response pathways. We also observed activation of anti-apoptotic proteins in retinoblastoma compared to control. These observations showed activation of survival pathways and signalling networks activated in tumors.