Clinicians face an increasing occurrence of invasive fungal infections. These are due not only to traditional yeast and mould species but also to rare pathogens that can be difficult to treat. The introduction of new agents has expanded the options for treating common and rare mycotic infections with antifungal efficacy at least equal, and safety far superior, to that of a once-limited choice of therapies. Patients with invasive mycoses frequently have concomitant disorders and require multidrug regimens. Clinicians must be aware of the potential for interactions among agents available for treating invasive mycoses in patients with serious underlying conditions.