The purpose of this study is to describe the reasons 88 Latinas with breast cancer selected specific supportive others to participate in an 8-week psychosocial intervention. Participants were asked one open-ended question during the baseline assessment for a larger clinical trial: “Could you tell me more about why you selected [insert name] to participate in the study with you?” A content analysis of the responses found three thematic categories: source of informational or emotional support, concern for the informal caregiver’s welfare, and special characteristics or qualities of the informal caregiver. These findings reflected both the cultural value of familism, the woman’s role as caregiver to the family (marianismo), and the man’s role of provider (machismo). Findings provide support for including the supportive person identified by the patient during a health crisis rather than the provider suggesting who that should be. Psychosocial services designed and implemented through such a cultural lens are more likely to be successful.