Data from 659 patients with a diagnosis of lupus nephritis were retrospectively collected among 32 nephrology centers in Italy, as a result of the collaborative effort of the Gruppo Italiano per lo Studio della Nefrite Lupica (GISNEL, Italian Lupus Nephritis Study Group). The overall probability of renal survival was 80% 10 years after the diagnosis. The probability of maintaining life-supporting renal function was evaluated according to several variables (clinical characteristics at presentation, World Health Organization [WHO] histologic classification). The presence at the time of diagnosis of hypertension and diffuse proliferative nephritis (WHO class IV) was associated with a worse prognosis.