OBJECTIVES There are no detailed assessments for Brazil regarding the prevalence of chronic pain. The literature describes prevalence of 8% to 60%. The objective of this study is to estimate the impact of this disease on a population of a private health plan and the association with financial expenses. METHODS An epidemiological survey was performed on 46,407 beneficiaries (37.8% from the global life coverage), 4,700 of whom referred a variety of symptoms, including 1,469 (31%) with pain complaints. Primary data, concerning expenses with hospitalization and use of medical services during a period of 12 months, of beneficiaries who referred pain, were analyzed and compared with those of individuals without this symptom. Data, based on a pharmacy benefit program, concerning 54,843 units of reimbursed medications, was collected to identify the most frequently drugs used for this symptom. RESULTS From the beneficiaries who mentioned pain, 30% were predominantly in the lower limbs, 30% low back pain, 18% joints, 9% abdomen and 14% other kinds. The correlation between two groups demonstrated that patients who had chronic pain had a 2.6 higher use of physician and hospital services (clinic, exams and inpatient care) and an annual expenditure per capita of U$ 581.35 compared to $ 233.55 in the group without pain complaints (p<0.001). Among the most frequently reimbursed medications, 36% were products commonly used for pain relief: 10.5% non steroidal anti-inflammatory drugs, 9% antiepileptic, 7.3% non opioid; 4.4% ansiolytics, 3.8% antidepressant and 1% neuroleptic drugs. CONCLUSIONS This epidemiological survey and the correlation with pharmacy benefit data, demonstrated a high prevalence of spontaneous pain complaints and a higher demand of the health insurance resources by those patients who mentioned this symptom spontaneously. The findings of this study suggest the need implementing effective support measurements for chronic pain patients.