This paper aims to explore the determinants of adoption of pharmacogenomics (PGx) testing by clinicians, and to assess whether this adoption differs with regard to area of specialization. Data were collected from a web-based survey among physicians in Québec (Canada). Our results highlighted that they perceived several benefits and had favorable attitudes toward PGx tests, but felt unprepared to use them. Results also show that practice specialties matter. Notably, being a family physician decreases the likelihood of adopting PGx tests. This might be explained by the fact that they perceived fewer benefits, used fewer sources of information, and received less training in PGx than their colleagues in other specialties. This is of particular concern given that family physicians are at the forefront of the healthcare system. Overcoming two knowledge barriers, that is, lack of information and clinical guidelines on PGx tests, might enhance physicians' readiness to adopt PGx testing.