Pii: 0040-9383(79)90034-x

IN THIS note we extend to the 3-dimensional case the results of M. Kreck on bordism of diffeomorphisms [3]. Some of this work is from the author’s doctoral dissertation [S]. It is a pleasure to acknowledge my indebtedness to Robion Kirby for his insight and encouragement. We also thank the referee for a careful reading and many useful suggestions. First recall the bordism relation for ditfeomorphisms introduced by Browder in [l]. Two orientation preserving diffeomorphisms hi: Mi + Mi of closed, oriented m-manifolds Mi(i = 0, 1) are bordant if there is an oriented bordism W between MO and MI and an orientation preserving diffeomorphism H: W -+ W such that HIMi = hi. The collection of bordism classes forms an abelian group A,,, under disjoint union. In [2], after several partial results by Winkelnkemper [9] and Medrano 141, Kreck proved