This report is designed for use by those specializing in the preparation of elementary and middle school principals and by those whose focus is on the inservice aspects of professional development. The paper identifies the proficiencies for K-8 principals and groups them into four major categories. The report elaborates on these categories, together with abilities and skills that K-8 principals develop with professional preparation and continuing activities. "Experience and Education" is the first of the four major categories of proficiencies; this section looks at the knowledge, expertise, and attitudes characteristic of the effective principal in four basic areas: child growth and development, training and learning processes, general knowledge, and school climate. Section 2,"Leadership Proficiencies," includes the categories of leadership behavior, communication skills, and group processes. "Supervisory Proficiencies," section 3, describes the principal's duties in relation to curriculum, instruction performance, and evaluation. The brief conclusion describes the principal's position as a continual learner. Appendixes provide two instruments to guide principals in assessing their own personal proficiencies and in establishing a plan for professional growth. Acknowledgments are included. (CJH)