At the meeting of the IWC Scientific Committee held in Dublin in May 1995, the special topic addressed by the sub-committee on small cetaceans was the North Atlantic harbour porpoise. A considerable body of new information was presented and we believe that it is important to include this in the present volume. What follows is a slightly edited version of the relevant sections of the report of the sub-committee on small cetaceans. The full version will be published in the Reports of the International Whaling Commission 46 in June 1996. We have edited the report to ensure that it can stand alone, occasionally shortening sections and including additional references. For ease we have used the same section numbering as in the original report. The papers referred to at the meeting are all cited in their unpublished form here. Many of these have been submitted for publication in Rep. int. Whal. Commn 46 and are presently out for revision and anonymous review. The interested reader should consult Rep. int. Whal. Commn 46 when it is published.