The occurrence and characteristics of remissions in patients with systematic lupus erythematosus (SLE) have not been determined. We therefore studied this in a cohort of 667 patients and found that 156 patients had achieved at least 1 period of 1 year or more of treatment-free clinical remission. This represents an incidence density of 0.028 new cases/person/year. Remission occurred within the first 2 years of disease in 62 patients. The mean duration of first remission was 4.6 years (range, 1-21 yr), and 81 patients were still in the initial remission up until cutoff time. Half of the remaining 75 patients who flared after achieving remission have not entered again in remission. Twenty-six of the 38 patients who did remained in remission, and the remaining 12 had subsequent flares and remissions. Treatment-free remission accounted for a mean of 5.8 years, corresponding to half the time of follow-up. Remission was not limited to patients with mild disease: at least 41 patients achieved remission despite renal involvement, 19 had had neuropsychiatric lupus, 15 had had thrombocytopenia, and 8 had had hemolytic anemia. We also found that the longer the time lapse between the initial manifestation and the diagnosis of SLE, the less likely it was for a patient to enter into remission. There was a continuous increase in likelihood of achieving a first remission from the beginning of disease up to 30 years of disease duration, when it reached 70%. Patients who achieved remission had increased survival, independently of the effect of other disease manifestations that cause increased mortality. We conclude that a significant proportion of patients with SLE, including those with severe organ involvement, may become symptom-free and in need of no more medication, perhaps indefinitely. Our findings support the notion that, in general, SLE is a more benign disease than previously considered.