OBJECTIVE: to provide insight into pregnant women's experiences of participating in a large multi-centre randomised trial. DESIGN: qualitative semi-structured interviews. SETTING: six UK maternity units. PARTICIPANTS: women recruited to the Magpie Trial. The Magpie Trial was a trial of prophylactic anticonvulsants for women with severe pre-eclampsia. MEASUREMENTS FINDINGS: a number of major but related themes emerged regarding influences on the women's decision-making: unpredictability of pre-eclampsia; quality of information received; role of others in the decision-making process; perceived personal benefit from trial participation; and perception of voluntariness of joining. KEY CONCLUSIONS: the data presented give valuable insights into the women's views and experiences of decision-making. Research into many of the other elements of care given during pregnancy and childbirth is still needed, and with this need comes the ethical responsibility of researchers to ensure trials are performed in the most scientifically robust ways, which are also acceptable to women. To examine the experiences of those involved in trial participation and their views about doing so is a crucial way of advancing this. The QUOTE Study increases understanding of the experiences of women participating in a randomised controlled trial. IMPLICATIONS FOR PRACTICE: the general implication for practice is that procedures are needed that can improve the design and conduct of randomised trials and therefore ultimately enhance the experience for future women. Recommendations include informed consent should be tailored, recognising individual differences in the desire for information. For instance the time individuals need to make consent decisions varies, as do their desires to consult with family before agreeing.