Fatigue is commonly associated with cancer and its therapy. The assessment of fatigue became increasingly important in cancer patients, as clinical interview may not indicate the severity of fatigue. Subjective assessment of fatigue in multi-dimensions indicates the level of severity of fatigue clearly to therapist, and the scores can be used to monitor response to cancer therapy. This study showed that the Revised Piper Fatigue Scale in Malay is a reliable and valid assessment tool. In 112 patients receiving external radiotherapy for various cancers, there was no significant difference of fatigue levels between gender and age ranges. Fatigue was significantly worse in nasopharengeal carcinoma on radiotherapy, presumably due to higher dose of radiation