An ideal model for decision making in cancer is shared decision-making (SDM). Primary facilitators in this model are information-seeking about treatment options and patient-physician trust. Previous studies have investigated the role of each of these parameters individually. However, little is known about their convergent role in treatment decision-making. Therefore, we explored perspectives of metastatic breast cancer (MBC) patients and healthcare professionals about the influence of health information-seeking and physician trust in the SDM process. Qualitative interviews with 20 MBC patients and 6 community oncologists, as well as 3 separate focus groups involving lay navigators, nurses, and academic oncologists, were conducted, recorded, and transcribed. Qualitative data analysis employed a content analysis approach, which included a constant comparative method to generate themes from the transcribed textual data. Five emergent themes were identified (1) physicians considered themselves as the patients’ primary source of treatment information; (2) patients trusted their physician’s treatment recommendations; (3) patients varied in their approach to seeking further health information regarding the discussed treatment options (e.g., internet websites, family and friends, support groups); (4) other healthcare professionals were cognizant of their fundamental role in facilitating further information-seeking; and (5) patient and physician discordant perspectives on shared decision making were present. Patient procurement of treatment information and the capacity to use it effectively in conjunction with patient trust in physicians play an important role in the shared decision-making process.