We construct a trace on the algebra of classical elements in Boutet de
Monvel's calculus on a compact manifold with boundary of dimension n
> 2. This trace coincides with Wodzicki's noncommutative residue if th
e boundary is reduced to the empty set. Moreover, we show that it is t
he unique continuous trace on this algebra up to multiplication by a c
onstant. (C) 1996 Academic Press, Inc.