Angiotensin-converting enzyme (ACE) inhibitor therapy has been reported to improve patient survival and promote recovery of renal function in the renal crisis of systemic sclerosis. In addition, an ACE inhibitor and a calcium channel blocker have been reported to control hypertension and reverse dialysis-dependent renal failure in a patient with undifferentiated connective tissue disease. We treated a patient with undifferentiated connective tissue disease who developed hypertension, pulmonary compromise, and renal failure requiring prolonged dialysis therapy. Due to allergy, the patient's hypertension could not be treated with ACE inhibitors initially, yet pulmonary function improved and renal function partially recovered with tenormin and minipress. When blood pressure became refractory to tenormin and minipress after 14 months of peritoneal dialysis, the patient was treated with lisinopril alone. Pulmonary function has remained stable and the patient has been off renal replacement therapy for 26 months, with a further substantial increase in creatinine clearance following treatment with lisinopril. The delayed and sustained recovery of renal and pulmonary function in the present case suggests undifferentiated connective tissue disease, like systemic sclerosis, may benefit from therapy with ACE inhibitors.