Following a brief review of research and literature regarding the needs of secondary school substitute teachers, suggestions for helping these teachers do an effective, professional job are offered. Research indicates that understanding of the subject matter along with understanding of various learning approaches enhances the substitute teacher's professionalism and makes the job easier. Other environmental factors such as class size, student abilities, time of year, and day of week affect the responsiveness of students to learning and to the substitute teacher. Substitute teachers must show the same degree of good judgment skills and flexibility as the full-time teacher. In short, effective, successful substitute teaching seems to require an expansion and magnification of effective characteristics of all teachers. (CB)