BACKGROUND: Although commonly used in combination with irinotecan or oxaliplatin (iri/oxal) for treatment of colorectal liver metastases before extirpation, the effects of preoperative bevacizumab on surgical outcomes are not established. The objective of this retrospective study was to determine if addition of bevacizumab to iri/oxal preoperative chemotherapy increases morbidity after hepatic resection. STUDY DESIGN: We compared demographics, clinicopathologic data, treatments, and postoperative outcomes between patients given preoperative iri/oxal with and without bevacizumab and patients who underwent hepatic resection within and after 8 weeks from the last dose of bevacizumab. RESULTS: From 1996 to 2006, 96 patients were treated with preoperative iri/oxal; 39 (40.6%) received concurrent bevacizumab. Preoperative bevacizumab treatment was associated with less blood loss (median 425 mL versus 600 mL, p=0.01) and lower RBC transfusion rates (43.9% versus 23.1%, p=0.06) after partial hepatectomy on univariable analysis. Only age>or=70 years (hazard ratio=8.52, 95% CI [2.00 to 36.45]) and concurrent extrahepatic procedures (hazard ratio=4.12, 95% CI [1.49 to 11.39]) independently predicted RBC transfusion and overall complications, respectively. There were no differences in overall (43.6% versus 38.6%), severe (28.2% versus 24.6%), hepatic (17.9% versus 26.3%), wound (10.3% versus 7%), or thromboembolic or bleeding (2.6% versus 5.3%) complications (all p > 0.05). For patients treated with iri/oxal and bevacizumab, overall complications were more common when resection was performed within 8 weeks after the last bevacizumab dose (62.5% versus 30.4%), but this difference was not statistically significant (p=0.06). CONCLUSIONS: If discontinued at least 8 weeks before hepatic resection, addition of bevacizumab to preoperative iri/oxal does not increase morbidity after hepatic resection.