Analogous to critical values (CVs) in clinical pathology, occasional diagnoses in surgical pathology could require immediate contact of the physician to rapidly initiate treatment. However, there are no established CV guidelines in surgical pathology. We studied the incidence of CVs in surgical pathology by retrospective review of 2,659 surgical pathology reports and surveyed the perceptions of 5 clinicians and 11 pathologists about CVs in surgical pathology. We identified 13 CV cases (0.49%); 4 of the 13 reports documented phone calls to the clinician (most at least 1 day before final sign-out), and in 2 other reports the requisition included clinical history that implied previous knowledge of the diagnosis. The survey results indicated that for most diagnoses there was a range of opinions about whether immediate treatment was necessary and the need for a stat phone call. CVs occur in surgical pathology, but often there is no documented phone call in the surgical pathology report. Because there is little agreement about which diagnoses require a phone call and the degree of urgency, a consensus conference might prove useful for establishing surgical pathology CV guidelines and could represent a practice improvement.