Men who have a family history of breast and/or ovarian cancer may be offered a predictive genetic test to determine whether or not they carry the family specific BRCA1/2 mutation. Male carriers may be at increased risk of breast and prostate cancers. Relatively little is known about at-risk men's decision-making about BRCA1/2 testing. This qualitative study explores the influences on male patients' genetic test decisions. Twenty-nine in-depth interviews were undertaken with both carrier and noncarrier men and immediate family members (17 male patients, 8 female partners, and 4 adult children). These explored family members' experiences of cancer and genetic testing, decision-making about testing, family support, communication of test results within the family, risk perception and risk management. Implicit influences on men's testing decisions such as familial obligations are examined. The extent to which other family members--partners and adult children--were involved in testing decisions is also described. It is demonstrated that mothers of potential mutation carriers not only perceive themselves as having a right to be involved in making this decision, but also were perceived by their male partners as having a legitimate role to play in decision-making. There was evidence that (adult) children were excluded from the decision-making, and some expressed resentment about this. The implications of these findings for the practice of genetic counseling are discussed.