Abstract. For a ring R with an automorphism σ, an n-additive mapping∆ : R × R × ··· × R → R is called a skew n-derivation with respect toσ if it is always a σ-derivation of R for each argument. Namely, if n − 1of the arguments are fixed, then ∆ is a σ-derivation on the remainingargument. In this short note, from Breˇsar Theorems, we prove that askew n-derivation (n ≥ 3) on a semiprime ring R must map into thecenter of R. Let R be a ring with an automorphism σ. Recall that an additive mappingµ : R → R is called a σ-derivation if µ(xy) = σ(x)µ(y) + µ(x)y holds for allx,y ∈ R. An n-additive mapping∆ : R ×R ×···×R → R(i.e., additive in each argument) is called a skew n-derivation with respect toσ in the sense that if n−1 of the arguments are fixed, then ∆ is a σ-derivationon the remaining argument. Namely, if a 1 ,...,a i−1 ,a i+1 ,...,a n ∈ R are fixed,then for all x i ,y i ∈ R, we have∆(a 1 ,...,x i +y i ,...,a n ) = ∆(a 1 ,...,x i ,...,a n ) +∆(a 1 ,...,y i ,...,a n )and∆(a 1 ,...,x i y i