Delayed diagnoses in cancer may commonly be caused by cognitive errors or logistical breakdowns. These delays can lead to poor patient outcomes and are a frequent cause of malpractice lawsuits in the ambulatory setting. In this study, four electronic triggers were developed to detect patients at risk for delayed diagnosis of prostate and colorectal cancers. The algorithm identified patients with elevated prostate-specific antigen levels, positive fecal occult blood tests, iron-deficiency anemia, or bright red blood per rectum, but automatically excluded those that already received appropriate care or had known terminal illnesses. The positive predictive values for each these triggers were between 58% and 70%, providing a reasonably accurate report of patients that truly lacked appropriate follow-up. The American Medical Association has identified better follow-up of abnormal test results as a key area for improving patient safety in the ambulatory setting.