In Canada, high stakes objective structured clinical examinations (OSCEs) administered by the Medical Council of Canada have relied exclusively on physician examiners (PEs) for scoring. Prior research has looked at using SPs to replace PEs. This paper reports on two studies that implement and evaluate a standardized patient (SP) scoring tool to augment PE scoring. The unique aspect of this study is that it explores the benefits of combining SP and PE scores. SP focus groups developed rating scales for four dimensions they labelled: Listening, Communication, Empathy/Rapport, and Global Impression. In Study I, 43 SPs from one site of a national PE-scored OSCE rated 60 examinees with the initial SP rating scales. In Study II, 137 SPs used slightly revised rating scales with optional narrative comments to score 275 examinees at two sites. Examinees were blinded to SP scoring and SP ratings did not count. Separate PE and SP scoring was examined using descriptive statistics and correlations. Combinations of SP and PE scoring were assessed using pass-rates, reliability, and decision consistency and accuracy indices. In Study II, SP and PE comments were examined. SPs showed greater variability in their scoring, and rated examinees lower than PEs on common elements, resulting in slightly lower pass rates when combined. There was a moderate tendency for both SPs and PEs to make negative comments for the same examinee but for different reasons. We argue that SPs and PE assess performance from different perspectives, and that combining scores from both augments overall reliability of scores and pass/fail decisions. There is potential to provide examinees with feedback comments from each group.