Few studies have explored with standard measures patient satisfaction with care at the time of the diagnosis through rapid diagnostic pathways. This study aimed to assess satisfaction levels at the time of the diagnosis in a One-Stop Breast Unit and to examine associations with psychological states. An anonymous cross-sectional survey was conducted at a single center's One-Stop Breast Unit, to assess patient satisfaction regarding several aspects of the Unit. Two days after the diagnosis, 113 participants completed self-reported questionnaires evaluating satisfaction (Out-Patsat35), anxiety (State Anxiety Inventory), and psychological distress (Distress Thermometer). Overall, patients were very satisfied (80.7±20.7) with the One-Stop Breast Unit. The highest mean satisfaction scores concerned nurses' technical skills, interpersonal skills and availability. The lowest mean scores concerned physicians' availability, waiting time, and the provision of information. The results revealed a significant association between high state anxiety levels, lower levels of satisfaction with doctors' interpersonal skills (r=-.41, P<.001) and lower levels for information provided by nurses (r=-.38, P<.001). Moreover, greater psychological distress was associated with less satisfaction with the different aspects of care (doctors' interpersonal skills, doctors' availability and waiting-time). The results of regression models showed that doctor-related satisfaction scales explained 20% of the variance in anxiety (P<.01). Facing cancer diagnosis remains a stressful situation. However, our study suggested that a substantial part of this anxiety is sensitive to the quality of the patient-doctor relationship. Consequently, further efforts should be expended on adapting patient-doctor communication to improve patient reassurance.