Background: The number of multiple pregnancies has been significantly increased in the last decades due to assisted reproduction techniques development. Compared to singleton, twins and multiple pregnancies are associated to more complications and risks for both mother and children. The objective of this study was to examine the proportion of patients preferring a multiple birth over a singleton after an IVF/ICSI attempt, their reasons and the influence of socio-demographic and clinical parameters on their preference. Methods: A prospective study was conducted in two different Spanish centers in 2014; a public university hospital and a private clinic, with different populations and embryo transfer policies. In order to evaluate patients and partners attitudes towards twins and singletons, an anonymous 10-question survey was conducted and 399 were invited to participate. Results: 58.2% of participants preferred having twins to having one child at a time and 4.8% preferred triplets. Primary reasons for preferring twins were "avoiding a new IVF/ICSI attempt" (61.6%), "I like the idea of having twins" (27.3%), "avoiding the waiting list" (5.8%), and "in my opinion with the latest technology, the rate and severity of complications in multiple pregnancies are low" (5.2%). The multivariate analysis showed that the only significant parameter related to a preference for multiplets was the transfer of women’s own fresh embryos (OR=3.31). Conclusion: Twin pregnancy risks are not perceived as important by the majority of IVF/ICSI couples, and many of them specifically prefer twins. In our opinion, much more information is needed highlighting the multiple pregnancy risks and that information should come from medical sources besides general media.