See Article on Page 259-265The current National Comprehensive Cancer Network guideline for colon and rectal cancer designates that positron emission tomography-computed tomography (PET-CT) does not supplant a contrast-enhanced diagnostic CT scan. PET-CT should only be used to evaluate an equivocal finding on a contrast-enhanced CT scan or in patients with strong contraindications to IV contrast [1, 2]. In addition, as of 2015, the Korea Health Insurance Review & Assessment Service will not pay for PET-CT as a routine follow-up test. In this regard, colorectal surgeons should be cautious when planning PET-CT as an initial staging modality in clinical practice.PET is a promising tool as a preoperative imaging modality for colorectal cancer, but still lacks firm evidence supporting its use as a routine test. In this issue of the Annals of Coloproctology, Yi et al. [3] demonstrated effectively that preoperative PET-CT is useful in detecting regional and distant node metastasis in patients with colon cancer. Previously, Yoo et al. [4] had observed that preoperative PET-CT was useful in the detection of synchronous distant metastases (7.8%) and multiple primary malignancies (5.3%) in patients with colorectal cancer. Lee and Lee [5] also showed that preoperative use of PET-CT had resulted in a change in the treatment plan in 7% of colon-cancerpatients when compared to the use of multidetector CT. In a recent meta-analysis, PET-CT showed, on a per patient basis, the highest sensitivity (94.1%) for the initial detection of liver metastases when compared to CT (83.6%) and magnetic resonance imaging (88.2%) [6]. All these retrospective findings are valuable; however, before the preoperative use of PET-CT can be incorporated into clinical practice, such use must be validated through large prospective trials.