Sixty-four evaluable patients with hepatic metastases from colorectal carcinoma, who did not have evidence of extrahepatic disease, were treated with intrahepatic (IH) mitomycin C (M) after disease progression or intolerance to treatment with IH fluorodeoxyuridine (FUDR). Eleven patients (17%) had a partial response (PR) to IH M and ten (16%) patients had stable disease. Patients who responded to IH FUDR were more likely to respond to IH M when compared with those who progressed on IH FUDR (47% versus 13%, respectively; P = 0.013). Those who were switched to IH M because of hepatotoxicity on IH FUDR also were more likely to respond to IH M than those who were switched because of progression on IH FUDR (75% versus 27%, respectively; P = 0.022). Baseline laboratory values, the percent of tumorous liver involvement, prior history of systemic chemotherapy, and the interval from diagnosis to initiation of IH M did not help predict response. Toxicity was mild and well tolerated. The overall median survival time of the 64 evaluable patients was 9.0 months from the start of IH M therapy. We conclude that IH M has some salvage benefit in patients with hepatic metastases.