Background: Many biobanks rely upon patients' willingness to donate biospecimens and healthcare professionals to initiate opt-in consent processes. This study explored if: (1) patients accept opt-in or opt-out consent models with varying levels of professional involvement; (2) professionals discuss participation with specific patient groups; and (3) this discussion is associated with patient knowledge of biobanking processes., Methods: Outpatients completed surveys at a tertiary cancer center in New South Wales, Australia. Eligible participants were English-speaking adults who recently had cancer-related surgery. Participants completed 27 questions exploring acceptable consent models, biobanking experiences, knowledge, and willingness. Logistic regression and chi-square tests examined differences in the characteristics and knowledge of participants who were offered the opportunity to participate versus those who were not., Results: A total of 113 outpatients participated (97% response). Most participants (92%) found opt-out, patient-initiated consent acceptable; however, high acceptability was reported for all models except for opt-in, patient-initiated consent (58%). University or technical qualifications (P = 0.001) was associated with increased odds (OR = 4.5) of being offered biobanking. The majority did not know what occurred to samples after surgery (59.3%) or pathology review (81.4%) and ability to answer these questions was associated with discussion of participation (P < 0.001). Of the few outpatients who discussed biobanking with their doctor (29%), all consented., Conclusion: Professional-initiated, opt-in consent resulted in a few educated patients being approached; greater professional initiation of consent would be fruitful as most patients were willing to participate if asked. However, other consent approaches minimizing professional involvement were as acceptable to participants warranting further consideration., (© 2018 John Wiley & Sons Australia, Ltd.)