[en] Introduction: Colorectal cancer (CRC) is cancer that takes its origin in the large intestine (colon) or the rectum (end of the colon). CT, MRI and transrectal ultrasound are relatively new modalities for evaluation of CRC. Objective: To determine the diagnostic accuracy of spiral CT scan for colorectal carcinoma taking histopathology as gold standard. Material and Methods: Cross sectional study was carried out in Department of Radiology, Jinnah Post graduate Medical Centre, Karachi from May 03, 2017 to December, 02 2017. A total of 66 patients of CRC meeting the inclusion criteria as defined in operational definition were enrolled in the study. Spiral CT was performed using Toshiba spiral CT scanner machine, having 16 slice capabilities. Images were reviewed by consultant having more than 5 years of experience. Patients histopathological report was taken from the laboratory. Results: Mean (±SD) age was 58.4±9.1 years with Male: Female = 1.6: 1. Sensitivity, specificity, positive predictive value and negative predictive value of spiral computed tomography for colorectal carcinoma were 96.7%, 80%, 98.3% and 66.7% respectively. Diagnostic accuracy of spiral computed tomography came out to be 95.5%. Conclusion: The results of study suggested that spiral computed tomography can be used as first choice diagnostic test and has potential to replace the lengthy tiresome colonoscopic procedure in the investigation of colorectal carcinoma. (author)