Background/Aims: Resection of the liver is the standard therapeutic approach for patients with hepatic metastasis and is the only therapy with curative potential. The optimal timing of surgical resection for synchronous metastases has remained controversial. Methods: From January 1993 to December 2008, our strategy has been to use simultaneous resection for resectable synchronous colorectal and liver metastases. During this period, 115 patients underwent simultaneous colorectal and hepatic resection. We evaluated the short-term outcomes of these patients by reviewing operative and perioperative clinical data. Results: In patients with simultaneous resection, there was no evidence of colorectal complications associated with major hepatectomy or no evidence of hepatic complications related to rectal resection. But increased hepatic complications were apparent with major hepatectomy compared with minor hepatectomy (44 vs. 7.2%, p < 0.001) and patients with rectal resection had increased colorectal complications (23% in the rectal resection vs. 5.3% in the colectomy group, p = 0.034). Conclusions: Simultaneous major hepatectomy and rectal resection can increase the hepatic or colorectal morbidity, respectively. These patients may be considered for staged resections.