As the use of standardized patients (SPs) for education and assessment continues to grow, there becomes an ever-increasing cohort of patients in our clinical practices who have participated as SPs. The present study is part of a five-year longitudinal study to examine the impact of participation as a standardized patient on the perceptions of the standardized patient's own health care. SPs participating in the 1993, 1994 and 1995 Objective Structured Clinical Examinations (OSCE) for medical students at the end of their third year were requested to respond to mailed questionnaires before, immediately after and one year after their participation in the OSCE(s). Results indicated that, while overall the SP's perceptions of their interactions with their doctors were positive both before and after participation in the OSCE, as a group, their perceptions of their own health care was significantly worse at one year post-OSCE. Additionally, when divided according to SP experience, that is novice versus experienced SP, most of the items on which there were changes were mutually exclusive between the groups. If these significant negative changes are due to the SPs becoming more educated consumers of medical care, this can be seen as a positive outcome. However, if the changes are due to variables particular to the third-year medical student OSCEs themselves, debriefing of the SPs following their participation in the OSCE may be warranted.