Simple SummaryAlthough animals are extensively used in experimentation for diverse purposes, ethical concerns have led to reluctance among a certain sector of the population. To find out the opinions of the Spanish population regarding animal research, we conducted a survey, obtaining responses from more than 800 people. While the majority were in favor, some groups were more prone to be against animal experimentation. In addition, we observed that people’s opinions could be altered by reading media reports. We also observed that people did not know about the handling of animals or laws concerning animal testing. Furthermore, we found that people were against the use of animals for non-medical purposes. In general, the survey showed the variety of people’s opinions and their concern for animal welfare.AbstractSince the time of Hippocrates in the 4th century BC, animal research has been extensively used for various purposes up to the present day. However, the use of animals for research has also been controversial for a long time. We report the findings of a public, online questionnaire-based survey designed to assess the opinions of a sample of Spanish society regarding animal research. Demographic data and opinions were obtained from 806 respondents. The results indicated a high level of acceptance of animal research (73.1%). However, certain factors, such as completing the questionnaire immediately after a reading negative media report (OR = 2.41; 95%CI: 1.64–3.54;p< 0.001), being a woman (OR = 1.77; 95%CI: 1.24–2.53;p= 0.002) or having a non-scientific background (OR = 2.47; 95%CI: 1.76–3.47;p< 0.001), were associated with a tendency towards a more negative opinion. The opinions seemed to be influenced by gender, education level and by protest incidents reported in the media. Our results also indicate that a lot of information regarding animal welfare, such as care and handling protocols, along with legislation was unknown to individuals. Further, a growing popularity of companion species and opposition to animal experimentation for non-biomedical purposes were reflected in the responses obtained. The use of animals for research purposes emerged as a sensitive social issue in terms of concerns about animal ethics and welfare.