Background: The prevalence of constipation in patients with cancer is estimated at 50-90%. It is often associated with pain, anorexia, nausea and vomiting and impacts negatively on quality of life. Despite its common occurrence, it is often poorly recognised and treated by healthcare professionals. Methods: A national cross-sectional survey was conducted in Ireland to describe constipation prevalence and severity in patients attending cancer centres and to evaluate management efficacy. In-patients or patients attending day oncology wards in any of the country's eight designated cancer centres were eligible to participate. Participants were shown the Bristol Stool Chart and answered questions regarding stool appearance and sensation of incomplete defecation; they completed the Constipation Assessment Scale. Data on pain character and intensity, opioid use, and prescribed and over-the-counter laxative use were collected. Data were summarised using descriptive statistics. Significance of variations for continuous data were determined using t-tests. Conditional ordered logistic regression was undertaken to determine factors associated with constipation. Results: The dataset comprised 491 patients. 24.8% had been reviewed by specialist palliative care; 14.5% by the anaesthetic pain team. In total, 42.2% of respondents were taking step 2 or step 3 opioids. Constipation prevalence was 67.6%; 19.4% of patients had Constipation Assessment Scale scores indicating severe constipation. A total of 46% of the respondents were not taking any laxatives. Of those who were taking laxatives, 54.8% reported constipation symptoms. While opioid use was strongly associated with participants reporting higher scores, this association was not seen in those patients receiving specialist palliative care. Conclusions: Constipation remains a clinical problem in Irish cancer centres. Despite increased opioid use, patients receiving specialist palliative care were more likely to take laxatives and reported less constipation. Specialist palliative care practice should be studied in order to identify what are the transferable 'ingredients' of effective constipation management.