The shortage of donor organs for transplantation is an international problem. One promising option to meet the need is xenotransplantation (XTx; eg, pig-to-human). However, there are still questions surrounding XTx that must be answered before proceeding to clinical trials. The current work is a meta-analysis of articles published between 1985 and 2019 to analyze the factors most strongly associated with agreement and opposition toward the procedure. Although 80% (41/51) of the published studies were related to the opinions of patients, only three provided sufficient data for analysis. Thus, the bulk of what we really know about attitudes toward XTx comes from students, stakeholders, and hospital staff. The findings suggest that, before proceeding from the laboratory to clinical trials, more directed research is necessary from individual programs to achieve sufficient understanding of the attitudes of patients and the broader public, and the level of risk that is acceptable to these groups.