PURPOSE: It was our aim to determine baseline levels of testicular cancer and genetics knowledge among members of families with Familial Testicular Cancer (FTC). METHODS: This is a sub-study of an ongoing National Cancer Institute (NCI) multidisciplinary, etiologically-focused, cross-sectional study of FTC. We evaluated 258 male and female participants including testicular cancer (TC) survivors, blood relatives and spouses to assess factors associated with a Genetic Knowledge Scale (GKS) and Testicular Cancer Knowledge Scale (TCKS). RESULTS: Knowledge levels were generally low, with genetic knowledge lower than TC knowledge (p < 0.01). Men with a personal TC history scored highest on TC knowledge, while gender, age and education differentially influenced knowledge levels, particularly among unaffected relatives. CONCLUSIONS: Prior to identifying FTC susceptibility genes, we recommend tailoring FTC genetic education to the different informational needs of TC survivors, their spouses and relatives, in preparation for the day when clinical susceptibility testing may be available.