Intravenous pulse cyclophosphamide (IPC) was used to treat lupus interstitial lung disease in 2 patients. Vital capacity increased by 67-110% of baseline values with IPC treatment. Total lung capacity and diffusing capacity also improved. Dyspnea and other manifestations of lupus improved dramatically. This is the first report documenting the efficacy of the early use of IPC for acute and chronic interstitial lung disease associated with lupus.