Introduction: The Multiple Mini-Interview (MMI) format appears to mitigate individual rater biases. However, the format itself may introduce structural systematic bias, favoring extroverted personality types. This study aimed to gain a better understanding of these biases from the perspective of the interviewer. Methods: A sample of MMI interviewers participated in a series of primary and follow-up one-on-one semi-structured interviews. Interviews pursued subjects of perception of biases (including norming; applicant personality, appearance and behavior; and interviewer personality) associated with the MMI process. Emergent qualitative data analysis was performed using the constant-comparative method. Results: A number of perceived biases were identified by subjects, sub-grouped into cultural factors, personality factors, perception of prior preparation, concerns with norming, and biases associated with specific applicant characteristics. Discussion: While the MMI appears to help mitigate individual rater biases, our analysis suggests that raters perceive structural systematic biases may be introduced by the question type and format of the MMI itself. Whether rater awareness of these biases mitigates them, and whether these herald other unconscious biases is unknown.