Invasive aspergillosis (IA) is a major cause of mortality in immunocompromised patients. Substantial improvements of treatment have been achieved by the introduction of new antifungal agents including azoles (e.g. posaconazole) and echinocandins (e.g. caspofungin). However, mortality associated with treatment-refractory aspergillosis remains high. Preliminary data suggest that the combination of azoles and echinocandins may increase activity against refractory IA. The objective of the present study was to evaluate efficiency and safety of caspofungin plus posaconazole for salvage therapy in immunocompromised patients. In this monocentric, retrospective study, 31 hospitalised haematopoietic stem cell transplant recipients with IA refractory to primary treatment were treated with a combination therapy of caspofungin 50 mg a day and posaconazole 200 mg four times per day. Efficacy was assessed by signs, symptoms and the degree of pulmonary infiltrate regression. A favourable response was seen in the majority of patients (77%). In two patients (6%), clinical improvement, but no decline in pulmonary infiltrates, was observed. Five patients (16%) did not respond to combination therapy with a fatal outcome in four of them. Combination therapy was well tolerated. No patient discontinued treatment due to toxicity. This study indicates that the combination of caspofungin and posaconazole may provide an effective and tolerable therapy of IA in immunocompromised patients refractory to primary treatment.