OBJECTIVES: To analyze the use of health care resources and the associated costs in patients with opioid induced constipation (OIC). METHODS: An observational, retrospective, multicenter study was carried out in Spanish National Health System hospitals.  All patients were free of constipation at baseline and received opioids for at least 2 months. In order to determine patient resource utilization, a review of the patient records and patient-interviews were performed to all patients diagnosed with OIC. Patients were evaluated depending on response to oral treatment for OIC. The observation period was 2 months. The unit costs were obtained from Spanish databases (€ 2009). RESULTS: A total of 744 patients were included. Patients had a mean (SD) age of 64.2 (13.4) and 48% were male. During the study period, 46.6% of the patients developed OIC. Most of these were treated first with oral laxatives exclusively (67.7%), 63.8% responded to the treatment and 36.2% did not. Of the total number of patients with OIC, 61.5% required a visit to health care services. Forty-four patients required a visit to the Emergency Room (ER) and 26 were hospitalized with a median length of stay of 3 days. Overall mean total cost (SD) of constipation management was €271.08  (€621.22). Resource utilization in responders to oral laxatives was statistically significant lower than in non-responders. A higher percentage of non-responders required healthcare visits, ER visits, and hospitalizations (p<0.001). The mean cost (SD) for each responder was €115 (€230) compared to €442 (€810) for each non-responder (p<0.001).  CONCLUSIONS: OIC increases healthcare resource utilization particularly in patients with a poor response to oral laxatives. The economic burden of OIC was 3.8 times higher in non-responders than in responders.