Genetic testing is increasingly available in medical settings and direct-to-consumer. However, the large and growing literature on genetic testing decisions is rife with conflicting findings, inconsistent methodology, and uneven attention across test types and across predictors of genetic testing decisions. Existing reviews of the literature draw broad conclusions but sacrifice nuanced analysis that with a closer look reveals far more inconsistency than homogeny across studies. The goals of this paper are to provide a systematic review of the empirical work on predictors of genetic testing decisions, highlight areas of consistency and inconsistency, and suggest productive directions for future research. We included all studies that provided quantitative analysis of subjective (e.g., perceived risk, perceived benefits of testing) and/or objective (e.g., family history, sociodemographic variables) predictors of genetic testing interest, intentions, or uptake, which produced a sample of 115 studies. From this review, we conclude that self-reported and test-related (as opposed to disorder-related or objective) predictors are relatively consistent across studies but that theoretically-driven efforts to examine testing interest across test types are sorely needed.