This volume contains invited and refereed papers based upon presentations given in the IMA workshop on Computational Modeling in Biological Fluid Dynamics during January of 1999, which was part of the year-long program "Mathematics in Biology." This workshop brought together biologists, zoologists, engineers, and mathematicians working on a variety of issues in biological fluid dynamics. A unifying theme in biological fluid dynamics is the interaction of elastic boundaries with a surrounding fluid. These moving boundary problems, coupled with the equations of incompressible, viscuous fluid dynamics, pose formidable challenges to the computational scientist. In this volume, a variety of computational methods are presented, both in general terms and within the context of applications including ciliary beating, blood flow, and insect flight. Our hope is that this collection will allow others to become aware of and interested in the exciting accomplishments and challenges uncovered during this workshop.