A novel solid hydrogen transfer agent (SHTA) based on an organic polymer containing fused-aromatic-ring units, supported in an inorganic matrix, was prepared and tested as a hydrogen donor in the upgrading of a heavy crude oil and its 274 and 343 degrees C+ residua. The SHTA performance is compared with that obtained using a conventional liquid hydrogen donor (tetralin). Three sets of experiments were carried out in a batch reactor: (1) hydrovisbreaking (HVB), (2) HVB with added tetralin, and (3) HVB with added SHTA. The results showed that the use of tetralin or SHTA in the HVB reaction enhances upgrading of heavy oils compared with the experiments without a hydrogen donor (HVB alone). Moreover, lower coke formation and a higher yield of liquid products were observed. The results obtained when using the novel SHTA are equivalent to those obtained when using tetralin as a hydrogen donor in the upgrading of a heavy crude oil and its 274 and 343 degrees C+ residua.