Background: Pain is one of the most burdensome symptoms of cancer. Although cancer pain management is an integral component in the practice of oncology, many patients still complain of insufficient pain control. Therefore, there is a need to pursue and strengthen strategies on how to adequately and effectively manage cancer pain. This study aimed to determine the knowledge and attitudes of Filipino medical oncologists regarding cancer pain management. It also examined the practices and perceived barriers in managing cancer pain. Methods: This was a cross-sectional study which utilized a validated questionnaire designed to assess a physician’s knowledge on pain management and opioid therapy, perceptions of the adequacy of cancer pain management, and significance of various potential barriers in optimal cancer pain management. Results: Out of the 280 PSMO members practicing in the Philippines, 85 responded to the survey. Using numeric rating scales of 0 to 10, medical oncologists appeared to agree on their knowledge about opioid therapy as well as in their perceptions of pain management. Respondents have rated themselves highly (Med: 8; IQR 6-8) in their ability to manage cancer pain. There were similar responses to ascribing all potential barriers as significant in rendering optimal cancer pain management, with cost as the most considerable factor (Med: 8, IQR: 7-10). However, given two challenging clinical scenarios, 66% and 90%, respectively endorsed treatment decisions that were unacceptable to pain experts. Conclusions: In this study, Filipino medical oncologists have shown agreement on their knowledge but perceived significant barriers in cancer pain management, with cost as the most considerable factor. Educational strategies, positive attitudinal change, and multidisciplinary collaboration with pain or palliative care specialists should be strengthened to improve patient care.