A new injector for the superconducting linac ALPI is under construction at LNL. This linac (called PIAVE) will be able to accelerate ions up to uranium, for an equivalent voltage of about 8 MV, and will improve the performances of ALPI (presently injected by a 15 MV Tandem) both in intensity and ions species availability. We shall discuss the design choices adopted for PIAVE, with the use of two compact 80 MHz superconducting RFQ up to about 530 keV/u, followed by eight independently phased QWR (minor modification of those already installed in ALPI). This approach, made possible by a rather sophisticated beam dynamics design, allowed to concentrate the R&D effort on the development of the RFQ structure. Details like the optimization of the acceleration in the RFQ, the bunching system and the transition between the two RFQs will be discussed. ©1999 American Institute of Physics.