Despite their widespread utilization, little is known about the quality of pathologists' assistants' services. Pathologists' assistants' performance was compared with pathology residents' performance using the metrics of lymph node retrieval and tissue resubmission rates. Lymph node retrieval was calculated by retrospective review of surgical pathology reports from a sample of axillary dissection, mastectomy, and colorectal specimens. Tissue resubmission rates were calculated by retrospective review of a sample of general surgical pathology reports. Pathologists' assistants retrieved a significantly greater total number of lymph nodes compared with pathology residents; however, there was no difference in the total number of positive lymph nodes retrieved. Cases for which pathologists' assistants performed the gross examination had a significantly decreased resubmission rate compared with those performed by residents. In this setting, the gross examination performance of pathologists' assistants was equivalent to or superior to that of pathology residents. These results provide the first information available relating to pathologists' assistants' performance in surgical pathology.