The School-Age Care Environment Rating Scale (SACERS) presented in this booklet is a comprehensive rating scale for school-age child care programs that is based on criteria for developmental appropriateness for this age group. The SACERS is intended to be used in center-based care rather than in family child care homes. The booklet begins with an introductory section which discusses the development of the SACERS, including the rationale for its development, and a discussion of its reliability and validity. The second section contains instructions for using the SACERs. The third and largest section of the booklet contains the actual rating scale items and notes for clarification. An adaptation of the Early Childhood Environment Rating Scale (ECERS) (Harms and Clifford, 1980) to school-age programs, SACERS is composed of 43 items grouped under 6 subscales: Space and Furnishings, Health and Safety, Activities, Interactions, Program Structure, and Staff Development. A set of six supplementary items for centers with special needs children is included. Each item is arranged as a 7-point scale with descriptors for each of the odd numbers: (1) inadequate; (3) minimal; (5) good; (7) excellent. The last section of the booklet is a training guide for administration of the SACERS, with information on preparing to use the scale, conducting a practice observation, and determining rater reliability. Training activities and an answer key are included. (DR)