Rapid Prototyping (RP) and Rapid Tooling (RT) are well known processesfor rapidly develop new products and consequently reduce the time to market. InPortugal, many companies are still not exploring the full advantages of usingthese technologies for new products development and produce reduced runs.This work presents some results obtained with composite tools manufactured forthermoplastics injection. These tools are obtained by casting a aluminium filledresin or by arc spray metal tooling over Rapid Prototyping models.Different properties, such as: moulds roughness, hardness and the wear weredetermined and compared, and the suitability of these processes are evaluated torapidly produce prototype moulds to inject thermoplastic models and pre series