A programmed instruction unit in institutional purchasing for dietetic students was developed and evaluated. The unit is compact, simple to use, and could serve as an overview or review of institutional purchasing by dietetic students. Subjects were forty-five dietetic students in coordinated undergraduate dietetic programs, dietetic internships, and dietetic traineeships, with two institutions represented in each group. The programmed unit was effective, because cognitive achievement post-test scores were significantly higher (24 per cent) than pre-test scores. The unit was equally effective with the three groups, which did not differ significantly in pre- and post-test scores, gain test scores, or attitude toward programmed instruction scale scores at the end of the unit. Interns had higher grad point averages (GPA) than students in coordinated undergraduate programs. All students spent an average of 1 hr. completing the unit, although trainees used more times. An attitude scale showed favorable attitudes by the students toward programmed instruction. Significant positive relationships were found between pre-test scores and GPAs, and post-test scores and GPAs. A questionnaire showed that instructors liked the unit, found it useful, and would use it again. The findings of this study suggest that programmed instruction units in other phases of dietetic education could be developed and used to present factual material, give an overview of a topic, help students to review, and/or save time in classroom instruction.