Idiopathic pulmonary fibrosis is unlikely to respond to immunosuppressive therapies, and patients with idiopathic pulmonary fibrosis may be harmed by such therapy. In contrast, some forms of interstitial lung disease can respond well to treatment with immunosuppressive drug therapies. Such agents can, however, be associated with significant risk of adverse effects such as infection, diabetes, osteoporosis, myopathy, bone marrow suppression, hepatitis, urinary tract injury, and drug-induced pneumonitis. Treating clinicians must be aware of potential adverse reactions to any immunosuppressive drug that they prescribe for their patients, and they should implement appropriate pre-therapy screening (e.g., tuberculosis, hepatitis, renal insufficiency) and monitoring that is recommended to avoid/minimize risk during the treatment period. Some disorders (e.g., cellular non-specific interstitial pneumonia, organizing pneumonia, or sarcoidosis) may respond very well to immunosuppressive therapies including corticosteroids as monotherapy, and the use of steroid-sparing agents can minimize corticosteroid side effects and may enhance treatment efficacy for disorders such as sarcoidosis or connective tissue disease-associated forms of interstitial lung disease.