This study was conducted to explore the characteristics of and interrelationships between teacher efficacy and professional learning community in 19 schools participating in the Quest project at AEL, Inc. The Quest project is an applied regional research project that assists schools with educational reform efforts. The School Professional Staff as Learning Community instrument developed by S. Hoard (1997) and an AEL-developed Teaching Questionnaire containing 2 scales (perceptions of external and internal efficacy) based on work by T. Guskey were administered to staff in the 19 schools, with 624 responses received. Based on the Cronbach alpha reliability estimates, it was concluded that all three scales had satisfactory reliability. Elementary school teachers had a higher level of internal efficacy and a higher sense of a professional learning community at their schools than did the high school teachers. High school teachers had a higher level of perceived external efficacy regarding learning than did the elementary school teachers. The results support the 1994 finding of T. Guskey and P. Passaro that the external and internal scales measure two separate constructs of teacher efficacy that have an inverse relationship. Internal and external measures of teacher efficacy were not significantly related to perceptions of the school as a learning community. Teachers' years of experience had no bearing on their perceptions of internal or external efficacy or their perceptions of the school as a learning community. Implications for the design or implementation of Quest programs are discussed. (Contains 4 figures, 6 tables, and 12 references.) (SLD)