In a recent paper Pucci, Serrin and Zou [15] established a strong maximum principle (SMP) for a large of class of divergence-form inequalities, including singular elliptic operators. They considered div{A(|∇u|)∇u} − f(u) ≤ 0, u ≥ 0, (1.1) in a domain D ⊂ Rn, n ≥ 2, where f is a nondecreasing, continuous function in [0,∞) with f(0) = 0 and where the function A = A(t) satisfies (A1) A ∈ C(0,∞), (A2) t → tA(t) is strictly increasing in (0,∞) and tA(t) → 0 as t → 0. Introducing the functions F(s) = s 0 f(τ ) dτ and H(t) = t 2A(t)− t 0 sA(s) ds, and assuming that for δ > 0 δ 0 ds H−1(F(s)) = ∞ (1.2) and lim inf t→0 H(t) t2A(t) > 0, (1.3) it is proved in [15] that any nonnegative solution of (1.1) in D which vanishes at some point of D must vanish everywhere in D.CMMFONDAPFONDAP