Failure to recognize symptoms which signal cancer may delay contact with the medical care system, thus decreasing the chances of diagnosis at an early stage of disease. We investigated the determinants of cancer symptom recognition and delay in seeking medical care in a population-based sample of 625 newly diagnosed lung, breast and colorectal cancer patients. Although the majority (79.5%) of patients reported noticing symptoms prior to diagnosis, one quarter of these patients (24.7%) delayed longer than three months in seeking medical care. Contrary to the findings of research based on clinic samples, logistic regression analysis revealed that no demographic or social support factors were predictive of symptom recognition or delay, with the exception that older colorectal cancer patients were less likely to notice symptoms, but also less likely to delay. Lung and colorectal patients diagnosed with advanced disease were more likely to notice symptoms than patients with local disease. Results of a content analysis of patients' remarks indicate that breast cancer patients were significantly more likely than lung or colorectal cancer patients to attribute their symptoms to cancer (p less than .001). Symptoms common to lung and colorectal cancer appear to be attributed to other, less serious causes. Given the lack of demographic predictors of symptom recognition and delay in seeking care, we suggest that education programs address risk groups for specific cancers, rather than the general public as a whole, grouping together all cancers and cancer symptomatology.