  We report a Grand Canonical Monte Carlo simulation study of the liquid-vapor
interface of a model fluid exhibiting polydispersity in terms of the particle
size $\sigma$. The bulk density distribution, $\rho^0(\sigma)$, of the system
is controlled by the imposed chemical potential distribution $\mu(\sigma)$. We
choose the latter such that $\rho^0(\sigma)$ assumes a Schulz form with
associated degree of polydispersity $\approx 14%$. By introducing a smooth
attractive wall, a planar liquid-vapor interface is formed for bulk state
points within the region of liquid-vapor coexistence. Owing to fractionation,
the pure liquid phase is enriched in large particles, with respect to the
coexisting vapor. We investigate how the spatial non-uniformity of the density
near the liquid-vapor interface affects the evolution of the local distribution
of particle sizes between the limiting pure phase forms. We find (as previously
predicted by density functional theory, Bellier-Castella {\em et al}, Phys.
Rev. {\bf E65}, 021503 (2002)) a segregation of smaller particles to the
interface. The magnitude of this effect is quantified for various $\sigma$ via
measurements of the relative adsorption. Additionally, we consider the utility
of various estimators for the interfacial width and highlight the difficulties
of isolating the intrinsic contribution of polydispersity to this width.
