In this study, a teaching program was designed to improve preservice teachers' self-efficacy about the use of alternative assessment. The teaching program has three stages: workshop, observation, and teaching. Preservice teachers' opinions about the contribution of the teaching program to their professional development and the effect of the program on their self-efficacy were determined Data was collected through a survey, students' reflective journal, and interview. Results show that preservice teachers had understanding about alternative assessment and positive opinions about the teaching program. Furthermore, their self-efficacy toward use of the alternative assessment improved. The teaching program had positive contributions to preservice teachers' professional development.