In this paper, we give some optimal upper bounds for the Sugeno's integral of monotone functions. More precisely, we show that: If g : [0, ∞) → [0, ∞) is a continuous and strictly monotone function, then the fuzzy integral value p = {cauchy integral}0a g d μ, with respect to the Lebesgue measure μ, verifies the following sharp inequalities:(a) g (a - p) ≥ pfor the increasing case, and(b) g (p) ≥ pfor the decreasing case. Moreover, we show that under adequate conditions, these optimal inequalities provides a powerful tool for solving fuzzy integrals. Also, some examples and application are presented. © 2006 Elsevier Inc. All rights reserved.