Abstract The comparative approach has been advocated to overcome some flaws inherent to case studies. Here, the spread of homeopathy in the early nineteenth century is addressed through a comparison of the cases of Sweden and Brazil, where homeopathy met diametrically opposed fates. The parameters used for the comparison are the standard for studies on the early spread of homeopathy, such as the concept of the “introducer,” and reception by the medical and academic community, the government, and society at large. The results suggest that analysis of contexts, determinants, and the interactions of practitioners and institutions representing different health care approaches, whether dominant or alternative, seems to provide a more accurate picture of different moments in the global history of medicine.