With increased budget cuts and a shortage of funding sources, Cooperative Extension must have a reliable group of proficient volunteers to carry-out organizational goals. Developing an understanding of volunteer abilities will assist extension agents in preparing and utilizing volunteers. Self-efficacy theory provided the theoretical framework of this study. The purpose of this study was to develop an understanding of the teaching self-efficacy of Florida Master Gardeners. The questionnaire included the instructional efficacy construct from the Teacher Sense of Efficacy Scale (TSES) and questions about participant demographics. The sampled population was 613 adult Master Gardeners with a total response rate of 86%. The majority of participants were women, white, earned some type of higher education degree, and 56 years old or older. Participants felt at least "some influence" in their effective teaching responsibility as a volunteer educator. Education was the sole demographic characteristic that had a significant effect on instructional efficacy. Proficiently training and retaining adults as volunteer educators in the Master Gardener program extends the reach of Cooperative Extension throughout Florida's communities. (Contains 2 tables.)