ABSTRACTThis study describes an online public engagement experiment aimed at investigating how acceptance of animal-based research is affected by: (a) the presence of regulations that govern the use of nonhuman animals in laboratories, (b) the invasiveness of procedures, and (c) the use of genetically modified (GM) animals. To meet these aims, participants were asked if they were willing to accept the use of pigs in different scenarios involving agricultural research. Two-thirds of the 681 participants were female and the majority (58%) were young (19–29 years old) with college or university level education (62%). Participants came from 26 different countries, with the United States, Canada, and the United Kingdom being the top three countries represented. Participants who self-identified as being vegetarians, familiar with animal welfare, animal advocates, environmental advocates, and familiar with animal research were significantly more likely to be opposed to animal-based research. Older participants were significantly less likely to oppose animal-based research. Support significantly decreased when animal-based research involved an invasive procedure or GM animals. Support for invasive research significantly increased when regulation was in place, but regulation had less effect on acceptance of GM animal use. Comments provided by participants illustrated different decision-making strategies regarding different types of animal-based research. Given the increasing use of GM animals in research, more effort is required to understand people's concerns regarding this type of animal use and to determine how these concerns should be reflected in policy.