Background: Despite pain awareness and the development of treatment guidelines, cancer-related pain assessment and management remain suboptimal. Our objectives were to estimate the prevalence and severity of pain and its interference with daily activities, and evaluate adequacy of treatment in cancer patients in Lebanon. Methods: A total of 400 cancer patients aged 18 and above were interviewed at the American University of Beirut Medical Center surgical and medical oncology floors, outpatient clinics and chemotherapy units from March 2016-February 2017. The subjects covered were socio-demographics, clinical data, and presence of pain in the past month with use of the Brief Pain Inventory questionnaire. Descriptive statistics were conducted using t-test, chi-square and Fischer's exact tests. Pearson's correlation coefficients were used to examine relationships between pain severity and pain interference. Logistic regression was employed to determine risk factors for pain. Results: The majority of participants were Lebanese (76.0%), females (62.7%), married (80.2%), of Muslim faith (64.2%), of urban residence (85.8%), and with insurance plans (81.3%). Most had breast cancer (38.8%), were stage 4 (52.7%) and underwent a combination of surgery and systemic therapy (55.1%). The prevalence of pain in the past month was 29.8%. Among patients with pain, the highest proportion had moderate pain (37.8%) and around 46% received inadequate treatment. Conclusion: More awareness about cancer-related pain is needed to improve pain management and encourage referral to palliative care and pain specialists early-on in diagnosis of disease.