The purpose of this pilot study was to develop and evaluate an instrument for measuring Greek elementary physical educators' knowledge of student assessment. A multiple-choice questionnaire comprised of items about concepts, methods, tools, and types of student assessment in physical education was designed and tested. The initial 35-item questionnaire was revised for its content and face validity, and 22 items remained. Then, 98 elementary physical educators completed the latter version of the questionnaire within half an hour and in the presence of the researcher. After item analysis and reliability test, adequate difficulty and discrimination indexes, acceptable internal consistency and strong test-retest stability were demonstrated for the final 17-item questionnaire. It is concluded that Greek elementary physical educators' knowledge of student assessment can be evaluated with a brief, valid, and reliable instrument. (Contains 2 tables.)