In this study, we developed and validated a questionnaire to assess teachers' perceptions of their actual and preferred school-level environment, investigated whether teachers involved with Outcomes-Based Education (OBE) perceive the school-level environment differently from those who are not, and investigated factors in the school-level environment (such as resources and staff freedom) linked with a school's likelihood of successfully implementing OBE. The study involved modifying and validating an existing questionnaire to make it suitable for assessing the school-level environment in South Africa, as well as adding to the School-Level Environment Survey (SLEQ) the scales of Familiarity with OBE and Parental Involvement. Analysis of data collected from 403 teachers provides evidence for the validity and reliability of the new SLEQ-SA. MANOVA for repeated measures revealed a statistically significant (p less than 0.01) difference between teacher perceptions of their actual school environment and the one that they would prefer for all seven SLEQ-SA dimensions. When MANOVA was used to examine whether teachers involved in OBE perceive their school-level environments differently from those who are not, statistically significant differences emerged for two of the seven school-level environment scales, with teachers involved with OBE perceiving significantly more Familiarity with OBE and Work Pressure. The constraints faced by teachers are wide ranging and include a number of factors such as a lack of material resources and large class sizes. The results provide valuable information to policy-makers, principals and researchers that potentially could help to guide the implementation of OBE.