Clinicians often assume that patients who develop pulmonary symptoms and radiographic infiltrates while receiving cytotoxic chemotherapy have opportunistic pulmonary infection or chemotherapy-related interstitial lung disease. We describe two cases of rare complications of commonly used chemotherapeutic agents (gemcitabine-induced eosinophilic pneumonia and rituximab-induced hypersensitivity pneumonitis) that vindicate this assumption but a third case of scleroderma-associated interstitial lung disease that became clinically manifest in a patient who was receiving chemotherapy. The latter case highlights the need for vigilance for other causes of interstitial lung disease in patients receiving chemotherapy.