We obtained data from 124 volunteer instructors in adult literacy, using an instrument developed to assess what the volunteers knew about providing reading instruction to adults. Results showed that volunteers with bachelor's degrees or higher and those who had teacher's certificates were significantly more knowledgeable about providing reading instruction than those without these credentials. There was no significant relationship between knowledge of reading instruction and type of professional development or self-rating of preparedness for teaching. Volunteer instructors had about the same level of knowledge as part-time and full-time teachers. These results will contribute to a better understanding of the characteristics of volunteer instructors and their knowledge of how to teach reading. (Contains 5 tables.)