The Science Teacher Inventory of Need (STIN) is an 83-item instrument which assesses science teachers' perceptions of their professional needs. Items on the STIN are organized under seven categories: (1) specifying objectives for science instruction; (2) diagnosing and evaluating learners for science instruction; (3) planning science instruction; (4) delivering science instruction; (5) managing science instruction; (6) administering science instructional facilities and equipment; and (7) improving one's competence as a science teacher. Seventy-six items consist of a statement which describes a task a science teacher may be called upon to perform, followed by a coded scale and a blank line to indicate the exact nature of any item-associated need or to list specific topics of interest. The last item in each category is open-ended to relate needs which do not fit into any other items in that category. The instrument is judged to be both valid and reliable. Content and construct validity were determined by a panel of judges and factor analysis respectively. High reliability values (r=0.95) were obtained when a bilingual form of the STIN was field tested with a population of Jordanian teachers. The instrument is appropriate for measuring needs of science teachers in developing countries as well as other nations, given accurate translations are used. The STIN instrument and an optional STIN response sheet are included. (JN)