This study examines whether partner relationship quality influences fertility, and if so, in which direction and which aspects of relationship quality are relevant. Competing hypotheses are tested. One hypothesis assumes that higher relationship quality leads to higher rates of childbearing, as a high-quality relationship offers the most favourable environment to raise children. An opposite hypothesis expects that lower relationship quality leads to higher rates of childbearing, as couples might have children in order to improve their relationship. Hazard analyses are performed using three waves of the Panel Study on Social Integration in the Netherlands. Findings indicate that positive as well as negative interaction between partners has a negative effect on first- and higher-order birth rates. This suggests that couples are most likely to have children if they do not have too much negative interaction, but neither interact in a very positive way. Value consensus negatively influences higher-order birth rates. © The Author(s) 2008.