Objective:LipophilicMalasseziaspecies may induce catheter-associated sepsis in newborns and immunocompromised patients receiving parenteral lipids. Therefore, we tested whetherM. furfurand six otherMalasseziaspecies can use commercially available infusions as a lipid source.Design:Prospectivein vitrostudy.Setting:Research laboratory in a university hospital.Interventions:None.Measurements and Main Results:With the exception ofM. restricta,allMalasseziaspecies grow on lipid infusions. There are no substantial differences among the different brands. The most rapid growth is shown byM. furfur,which grows better on agar containing a 20% rather than a 10% lipid infusion. Growth ofM. furfurandM. sympodialiscan be reduced by infusions containing medium-chain triglycerides. Incubated in triglycerides,M. furfuris strongly suppressed by 50% medium-chain triglycerides andM. sympodialisby 8% medium-chain triglycerides. When medium-chain free fatty acids are added to triglycerides, both species can be suppressed by about 1% free fatty acids.Conclusion:Medium-chain triglycerides and medium-chain free fatty acids are toxic forMalasseziaspecies. Commercially available infusions containing medium-chain triglycerides might be used to prevent systemicMalasseziainfections.