The modern psychological investigation of passion started with the study by Vallerand et al. (2003). The construct of passion has been applied to sports, gambling, and performing arts. The application of the construct of passion to the field of teaching has been very limited. This study uses Vallerand et al.'s definition of passion to consider the teaching of five science teachers. Using a case study methodology five teachers, who had been teaching for nine to sixteen years, were each interviewed twice, three of the five teachers provided a lesson plan that they had developed, about which they were passionate. I found that each of the participants was passionate about their craft, that each enjoyed being able to develop their own curricula, and that each participant valued peer collaboration and sharing of ideas as a means of professional development. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]