OBJECTIVES: To compare patient reported quality of life in cancer patients on opioid therapy with and without constipation. METHODS: Patients with a diagnosis of cancer, receiving opioids from all public pharmacies in the Netherlands, were recruited by a pharmacy worker to complete a generic questionnaire about opioid use and constipation and the EuroQoL-5-Dimensions questionnaire (EQ-5D) about generic Quality of Life (QoL). Patients were classified as having constipation or not based on self-reported bothersome side effect of the opioid and use of laxatives. EQ-5D index scores were compared with Wilcoxon Two-group test. RESULTS: A total of 113 patients using opioids from 170 pharmacies returned the questionnaires. Seventy-five (66%) of the cancer patients were classified as having constipation. Patients with and without constipation were similar with respect to age (mean ±standard deviation 66.1±9.8 and 63.8±12.6, respectively), gender (44% and 50% males, respectively) and type of opioid (most frequently oxycodone, fentanyl and morphine preparations in both groups). Patients with constipation more often reported problems with Pain (95% versus 92%) and Anxious/depressed Mood (52% vs. 42%), but less often with Self care (52% vs. 58%) than patients without constipation. The median [25th-75th percentile] EQ-5D index score among patients with constipation was lower compared to those without constipation (0.39 [0.19-0.69] vs. 0.63 [0.30-0.78], p=0.10). CONCLUSIONS: Constipation in cancer patients using opioids has a substantial impact on patient’s quality of life. Alleviation of constipation symptoms might help improve patient reported quality of life.