Let V ⊂ R n be an algebraic set of positive dimension and let L ∞ (F ) be the Łojasiewicz exponent at infinity of a regular mapping F : V → R m . We prove that F has a polynomial extension G : R n → R m such that L ∞ (G) = L ∞ (F ). Moreover, we give an estimate of the degree of this extension. Additionally, we prove that if dim V < n − 2, then for any β ∈ Q, β < L ∞ (F ) the mapping F has a polynomial extension G with L ∞ (G) = β. We also estimate its degree.