Despite the ethical codes guiding bereavement research, few studies have been conducted to evaluate the perceived stress experienced by the bereaved, and to explore which methodologies cause least distress. This article investigates how bereaved and traumatised populations experience research participation, and they voice their recommendations for future research. The data are from a nationwide three-phase study in Norway among parents who had lost their child by suicide, SIDS, and accidents between July 1, 1997 and December 31, 1998. Whereas the first phase reported quantitative results of perceived psychosocial health and focused on offered and ideal support (N=262), the second phase investigated the same issues through in-depth interviews of a sub sample (N=69). Phase three, reported here, included the responses of 64 parents to a short questionnaire evaluating research participation in the two previous phases. The results show that 100% of the parents experienced participation as "positive"/"very positive", and none regretted participating. They linked the positive experiences to being allowed to tell their complete story, the format of the interview, and a hope that they might help others. Apparently, processes of meaning reconstruction and increased awareness of the bereavement process were facilitated by the interviews. However, three-quarters of the interviewees reported that it was to a greater or lesser degree painful to talk about the traumatic loss. Regression analysis showed that being a woman and high levels of psychic distress were the most important predictors of a painful interview experience. In order to protect bereaved and vulnerable populations from harm, already existing ethical codes must be strictly applied, and the researchers must listen respectfully to recommendations from bereaved parents.