Context:One of the principle obstacles identified in suboptimal management of pain in worldwide cancer patients is inadequate assessment of pain which in turn leads to poor management. In Sri Lanka, this is heralded by the lack of medical or nursing professionals qualified in Palliative Medicine/Care to date in Sri Lanka.Aim:The aims of this clinical audit were to raise awareness and optimize the assessment of pain among resident patients of a tertiary care cancer hospital by oncology doctors.Methods:A simple “pain and associated symptom chart” was designed for the doctors of the tertiary care cancer institution to document pain experienced by resident cancer patients in terms of intensity, both upon admission and on daily clerking. The expected standards were 100% documentation for each, regardless of the presence of pain on a visual analog scale (0–10). Documentation of the site and character of pain were expected to be 80% each.Results:Despite conducting three audit cycles with staff training and clarifications in between, the pain assessment practices did not be improve significantly (P > 0.05). In the third/ultimate audit cycle, it was noted that 23.5% of the charts were marked as “0” pain intensity upon admission and have been neglected thereafter.Conclusions:Pain assessment practices of the tertiary care oncology unit concerned was suboptimal. Therefore, it is of utmost importance to explore obstacles and incorporate pain assessment as a mandatory routine practice in clinical oncology units.