Sirolimus (rapamycin) and everolimus are immunosuppressive agents that inhibit cardiac allograft vasculopathy. Sirolimus has been widely used in renal transplantation, and its use in heart transplantation is increasing. Sirolimus-associated pneumonitis has been described in renal transplant patients. Two cases of sirolimus-associated pneumonitis have been reported after cardiac transplantation. Only 1 case has been described in detail, and this had a fatal outcome. Here, we present a case of sirolimus-associated interstitial pneumonitis in a cardiac transplant recipient that resolved completely with withdrawal of the drug and treatment with corticosteroids.