Our previous studies showed that early diagnosis of painful bone metastasis is difficult and requires improvement in the diagnostic accuracy of plain radiography during an initial patient consultation. In this preliminary study, we evaluate the usefulness of educational material used to improve diagnosis of bone metastasis with plain radiography. This study included imaging data from 129 consecutive patients who visited our orthopedic clinic during the period January 2011 through December 2014. First, we prepared a test to measure the reading ability of orthopedic practitioners, after which the educational material was created. Then, the effectiveness of the educational material was verified by having orthopedic trainees take a pre-test and post-test. The test contained plain radiographic data from 12 patients with lesions and 6 without lesions. The educational material included plain radiographic data from 30 patients with typical findings of bone metastasis, as well as diagnostic magnetic resonance images or computed tomography scans, accompanied by a lecture. The accuracy and sensitivity of diagnosis significantly improved after the lecture; however, specificity decreased. Although the educational material was effective for improving the ability of orthopedic trainees to read plain radiographs of bone metastasis, some aspects of the program need to be improved and revised.