The aim of this study was to compare pregnant women with a previous history of postnatal depression, attending a Tertiary Obstetric Unit in Belfast and a District General Hospital in Newry. Women with a previous history of postnatal depression recorded at booking for their most current pregnancy were studied between January 2001 and May 2002. A total of 443 women (6.6%) in Belfast had a history of postnatal depression, compared with 113 women (6%) in Newry. The most common age range was 31 - 35 years in both centres. Some 69% of women in Belfast compared with 81% of women in Newry were given treatment. Fluoxetine was the commonly prescribed drug for each centre. During this subsequent pregnancy, 19 women (4.3%) in Belfast and five women (4.4%) in Newry remained on antidepressants. There was one woman in each centre who took an overdose during this pregnancy. More women in Newry were given treatment. During the subsequent pregnancy, the percentages of women from each unit requiring antidepressant therapy were similar.