Few studies directly address vulnerable populations' motivation for participating in research. Often motives are expressed spontaneously and typically given post-interview. This article investigates motivation for research participation among informants who have been bereaved by suicide. Informants were specifically asked for their motivation either prior to, or directly after the interview. Four categories of motivations were identified: (1) Helping Others, (2) Venting, (3) Insight, and (4) Just Because. Sixty percent of informants gave more than one motivation. The majority was altruistically motivated; they hoped that by taking part they could play a role in helping to prevent suicide, improving services for the bereaved or moving research forward. Close family members were more likely to be motivated by a desire to help others than more distant family members. Findings are discussed in the context of suicide-related bereavements. Information about research participation as beneficial to others should be given parallel to that of possible strain.