Posaconazole (PCZ) is used mainly for the prevention of invasive fungal infection (IFI). A multicentre retrospective, investigational study using a non-randomized, single-arm design carried out in six tertiary hospitals in Spain to evaluate the use of PCZ in different forms of administration in the (non-prophylactic) treatment of IFI. Over an eight-year-period, 67 patients were included in this study. PCZ was administered as salvage therapy (intolerant or refractory to a previous antifungal agent) in 65/67 (97%); of these, it was used against Aspergillosis (68.6%), Zygomycosis (13.4%), other moulds (8.9%) and yeast (10.5%). The median duration of PCZ therapy was 75days. The oral solution was associated with low serum levels (<0.7mg/L) in 63% of available patients. Clinical response at 3 and 12months of PCZ therapy were for aspergillosis: 47.8% and 41.3%; for zygomycosis: 55.5% and 55.5%; and for other mycoses: 69.2% and 69.2%, respectively. Suspension by toxicity was only observed in 6% and 7.5% of patients at 3 and 12months, respectively, mainly with grade III/IV elevations of liver function test (LFTs). Posaconazole salvage therapy, especially oral tablets, can be an effective alternative option for patients with IFI who cannot tolerate or do not respond to other antifungal therapies.