Objective. The reported frequency of scleroderma M01-R renal crisis (SRC) in diffuse systemic sclerosis (SSc; scleroderma) is 15-20%. Early use of angiotensinconverting enzyme (ACE) inhibitors has markedly improved outcome. The present analysis reexamines the prognostic factors for and outcome of SRC in a prospective cohort of patients with early diffuse SSc.Methods. We retrospectively evaluated the cohort of SSc patients who participated in the High-Dose Versus Low-Dose D-Penicillamine in Early Diffuse SSc trial. Patients with diffuse cutaneous scleroderma were enrolled if their disease duration was <18 months. Because the trial failed to show a difference between treatment groups, the data were pooled.Results. One hundred thirty-four SSc patients entered the observation period a mean ؎ SD of 0.8 ؎ 0.3 years after onset of SSc. SRC occurred in 18 patients a mean ؎ SD of 0.9 ؎ 1.1 years after entry. During a mean ؎ SD 4.0 ؎ 1.1 years of followup after entry, 9 of the 18 patients died (mean ؎ SD 0.6 ؎ 0.9 years after SRC onset). Baseline characteristics that predicted SRC included a modified Rodnan skin thickness score of >20 (P < 0.01), enlarged cardiac silhouette on radiograph (P ؍ 0.04), large joint contractures (wrist, elbow, knee) (P ؍ 0.008), and prednisone use at entry (P ؍ 0.01). Baseline characteristics that did not predict SRC included age, sex, race, Health Assessment Questionnaire score, fist closure, handspread, lung involvement, muscle weakness, erythrocyte sedimentation rate, and platelet count. In 5 of 10 subjects for whom at least 2 sequential skin scores were available, skin scores increased significantly (P ؍ 0.012) in the 6 months before onset of SRC.Conclusion. SRC occurred in 13% of patients soon (mean 11 months) after entry into the cohort.