Background and Objective: We conducted a systematic review on diagnostic tests in primary care for identification of patients with an increased risk for colorectal cancer (CRC). We aimed to present the results in an informative way for primary care physicians. Data Sources: PubMed, EMBASE and reference screening. Study eligibility criteria: Studies were selected if the patients were adults consulting because of non-acute lower abdominal symptoms; tests included signs, symptoms, blood tests, or faecal tests. Study appraisal and synthesis methods: Two reviewers independently assessed study quality using the QUADAS tool and extracted data. We presented pooled estimates of sensitivity and specificity using bivariate analysis. We also calculated pooled estimates for the positive predictive value (PPV) and 1 minus the negative predictive value (1-NPV), representing the risk of CRC after a positive test result and after a negative test result, respectively. We refrained from pooling when there was considerable clinical or statistical heterogeneity. Results: Evidence for test performance in primary care was scarce and varied widely. In contrast to our expectations, however, PPV and 1-NPV more often showed statistical homogeneity than sensitivity and specificity. This enabled statistical pooling of predictive values for age, gender, rectal bleeding and constipation, where this was not possible for sensitivity and specificity. For example, sensitivity of constipation was very poor and specificity ranged between 0.53 and 0.90. Pooled estimates of predictive values clearly showed that constipation was not associated with an increased risk of CRC, with a pooled estimate for PPV of 0.06 (0.0 0.18) and 0.10 (0.07 0.14) for 1-NPV. When pooled estimates could not be presented ranges of predictive values were still of interest. Conclusions: Estimates of PPV and 1-NPV seem to provide clinically useful information. However, caution in their use is needed, and sources of heterogeneity and other prerequisites for meta-analysis of predictive values should be explored.