The evaluation of oncology patients represents a substantial volume of the workload in many radiology departments. Interpreting the results of oncologic examinations is often challenging and time-consuming because many abnormalities are identifed in the same examination and must be compared with the fndings in previous studies. However, errors in the interpretation of oncologic computed tomographic (CT) scans can have signifcant effects on patient care. These effects may range from withdrawal from a clinical trial or cessation of therapy to repeat CT examination because of a technically inadequate study, CT-guided biopsy of newly identifed lesions, or initiation of therapy for previously unrecognized lesions. A root cause analysis of reported errors in the interpretation of abdominal and pelvic CT scans led to the identifcation of potential pitfalls that may be encountered when interpreting oncologic CT scans and factors that contribute to these errors. Awareness of the spectrum of factors that contribute to misinterpretation of CT scans in oncology patients may improve the performance of the individual radiologist and ultimately translate into improved patient care.