BACKGROUND: The purpose of this study was to investigate attitudes towards the donation of surplus embryos among couples with cryopreserved embryos/zygotes, and to identify correlates associated with attitudes toward the destinations of surplus embryos/zygotes. METHODS: Eleven of 19 Swiss in vitro fertilization (IVF) centers in existence in 2004 participated in the survey. Questionnaires were sent to 888 eligible couples; 458 men (52%) and 468 women (53%) returned them. RESULTS: Fifty-two percent of the participants supported the donation of surplus embryos to other couples, but divided opinions on the disclosure of biological parents' identities were identified. About 70% of participants indicated that donations of surplus embryos for medical research or therapy should be allowed, following strict regulations. Multiple logistic regression analyses revealed couples' position on the moral status of an embryo as the strongest predictor of attitudes toward all destinations of surplus embryos. Having children due to IVF/Intra-Cytoplasmic Sperm Injection (ICSI) treatment was negatively associated with attitudes towards donations to other couples. Perceived importance of religion, age >40, being a resident of the French-speaking region and unsuccessful IVF/ICSI treatment experiences were predictive of supporting donations for medical research. CONCLUSIONS: Swiss couples with cryopreserved embryos/zygotes are open to different options related to donating, rather than discarding, surplus embryos.