Let {p(n) (x)}(n greater than or equal to 0) be the set of orthonormal poly
nomials with respect to the exponential weight w (x) = e(-v(x)), where v (x
) = x(2m) + ... is a monic polynomial of degree 2 m with m greater than or
equal to 2 and is even. An asymptotic approximation is obtained for p(n)(x)
, as n --> infinity, which holds uniformly for 0 less than or equal to x le
ss than or equal to O(n(1/2m)). As a corollary, a three-term asymptotic exp
ansion is also derived for the zeros of these polynomials.