The diagnosis of cancer-related neuropathic pain is often difficult for non-pain medicine specialists. We examined whether a Japanese version of a neuropathic pain screening questionnaire (Japan-Q), which was developed for chronic pain, is appropriate for screening cancer-related neuropathic pain. Methods: Our palliative care team screened 104 patients from May 2014 to December 2015 and compared total points of the Japan-Q with diagnosis of the type of cancer pain by specialized pain clinicians. Validity was evaluated using a receiver operating characteristic (ROC) curve. Results: The area under the ROC curve in terms of the total score, sensitivity, and specificity for the Japan Q was 0.82, which indicated a moderate level of diagnostic accuracy. A cutoff value of 3 points was shown to be best (sensitivity: 79%, specificity: 82%). When a cutoff value of 9 points was used as the diagnostic criterion for neuropathic pain, there was greatly reduced sensitivity (sensitivity: 40%, specificity: 97%). Conclusion: Although the Japan-Q shows moderate diagnostic accuracy related to cancer pain, the cutoff value for this tool is lower than that for chronic pain. Cancer-related neuropathic pain should be suspected with a total score of 3 or more in the Japan-Q.