To increase the therapeutic potential of these oncolytic viruses based on a 24 base pair deletion in the viral E1 A gene (D24), a conditionally replicating adenovirus targeting multiple receptors upregulated on tumors was generated by incorporating an Ad5/3 fiber with a carboxyl terminus RGD ligand. The virus displayed full cytopathic effect in tumor lines assayed at low titers with improved cytotoxicity over Ad5-RGD D24, Ad5/3 D24 and an HSV oncolytic virus. The virus was further engineered to deliver immunotherapeutic agents such as GMCSF while maintaining enhanced heterogenic oncolysis.