The delayed diagnosis of colorectal cancer (CRC) may be attributable to sociodemographic characteristics, to aspects of tumour histopathology or to the functioning of the health system. We seek to determine which of these factors most influences prolonged patient-attributable delay (PPAD) in the diagnosis and treatment of CRC. A prospective, multicentre observational study was conducted in 22 Spanish hospitals. In total, 1,785 patients were recruited to the study between 2010 and 2012 and underwent elective or urgent surgery. PPAD is considered to occur when the time elapsed between a patient presenting the symptom and him/her seeking attention from the primary care physician or hospital emergency department exceeds 180 days. A bivariate analysis was performed to assess differences in variables segmented by tumour location and patient delay. Multivariate logistic regression analysis was performed on the outcome variable, PPAD. The rate of PPAD among this population was 12.1%. PPAD was significantly associated with altered bowel rhythm (odds ratio OR, 1.36; 95% confidence interval CI, 1.02 to 1.83) and with adenocarcinoma histology, in comparison with mucinous adenocarcinoma (OR, 2.03; 95% CI, 1.11 to 3.71). Other sociocultural factors and clinicopathological features were not independent predictors of PPAD. Many patients do not consider altered bowel rhythm an alarming symptom, warranting a visit to the doctor. PPAD could be reduced by improving health education, raising awareness of CRC-related symptoms.