Liver resection is regarded as the treatment of choice in selected patients with hepatic colorectal metastases. Despite improvements in preoperative imaging, non-therapeutic laparotomy (NTL) is reported at varying rates. Some centers have advocated staging laparoscopy prior to laparotomy in order to reduce NTL. The aim of this study was to examine trends in NTL rates in patients undergoing planned surgical therapy for hepatic colorectal metastases at a single center. Data from 530 operations (461 patients) undergoing planned potentially curative surgical therapy for colorectal liver metastases between 1994 and 2005 were analyzed. Staging laparoscopy was not performed in any patients. Cases were grouped into three time periods and prevalence of NTL determined for each period. Overall, 49 NTL operations were performed during the study period (9.2%). Significantly higher NTL rates were seen in patients with multiple metastases, CEA >100, and tumor size >5cm. Preoperative PET imaging was associated with significantly lower NTL (5.6% vs. 12.4%, p=0.009, OR=0.42). At laparotomy, extrahepatic findings were the reason for NTL in 45% of cases. Patients undergoing surgery between 1994 and 1997 were found to have an NTL rate of 15.6%, compared with 9.1% between 1998 and 2001, and only 4.7% between 2002 and 2005 (p=0.003). Comparisons were made between time periods for a variety of patient, tumor, and treatment-related factors. PET imaging was performed more frequently over time (0%, 30%, and 91% respectively for each time period, p<0.001). Patients in each time period were similar with regard to other factors including tumor number, size, or use of ablation. The prevalence of NTL for patients undergoing surgical exploration for hepatic colorectal metastases has decreased significantly in recent years at our institution, most recently below 5%. The reasons for this trend are probably multifactorial and may include improved preoperative assessment, such as PET imaging, as well as salvage surgical options. Such low negative laparotomy rates call into question the utility of staging laparoscopy prior to open surgical exploration.