This multiple regression study analyzed the percent of variance in teacher efficacy of 106 student teachers and novice teachers in agricultural education in Ohio explained by selected variables related to perceived support (utilizing a mentor, supportive principal behaviors, collective efficacy), teacher preparation quality, and student teaching experiences. Collective efficacy, perceived teacher preparation quality, and perceived student teaching experience explained 17% of the variance in teaching efficacy at the 10th week of the school year. Although utilizing a mentor and supportive principal behaviors were eliminated from the model, perhaps these variables were not perceived as being as important as collective efficacy, perceived teacher preparation quality, and perceived student teaching experience during the first 10 weeks of the school year. (Contains 2 tables.)