The invention relates to an energy efficient, environmentally favourable process for the preparation of brominated rubbers, in particular bromobutyl rubber, that uses a common medium for both solution polymerization and subsequent bromination of the rubber and which further exhibits an enhanced bromine usage due to the use of a oxidizing agent. More particularly, the invention relates to a process that employs a common aliphatic medium for both solution polymerization and bromination of rubber in the presence of a brominating agent and an oxidizing agent with intermediate removal of un-reacted monomers.