Caspofungin is an echinocandin with potent antifungal activity against Aspergillus species. Its mechanism of action differs from that of the antifungal agents used so far, like amphotericin and azoles. It has proven effective and well tolerated and its use is therefore currently approved as salvage treatment in patients with invasive aspergillosis refractory to amphotericin, as well as for the empiric treatment of febrile neutropenia. Indeed it has been recently evaluated as empirical treatment in neutropenic patients with persistent fever of unknown origin and proved equally effective and better tolerated than liposomal amphotericin.