This paper summarises the findings of a study on second trimester abortion in England and Wales in 2005. Second trimester abortions constitute a relatively small proportion of the total number of legal abortions performed in these countries yet attract quite substantial public, and particularly media, attention. Discussion of these abortions has, however, been conducted within a context of little understanding of the factors which explain why they happen. This paper starts with a brief introduction to the policy context for provision of second trimester abortion, and a summary of existing research in the area. It then presents the results of a survey of 883 women on their own reasons why they had abortions in the second trimester. The key concept is that of "delay" and reasons for delay in seeking or obtaining abortion at five stages in the pathway to abortion. No clear, single reason emerges. Amongst the main reasons identified are uncertainty about what to do if they were pregnant, not realising they were pregnant, experiencing bleeding which may have been confused with continuing to have periods, and changes in personal circumstances. The paper ends with a consideration of the implications of the results for education, policy development and service provision.