Each classroom has its own assessment environment perceived by the students and springs from the teacher's assessment practices. Although students' perceptions of the assessment environment may influence their achievement-related outcomes, little attention has been given to the measurement of perceived classroom assessment environment. This study reports on the development and datametric properties of a scale measuring students' perceptions of the classroom assessment environment. A total of 450 students enrolled in the tenth grade English language classes at Muscat public schools in Oman completed the scale. Results yielded two subscales of the perceived classroom assessment environment: learning-, and performance-oriented environments. The correlations between them suggested that they represented unique aspects of the classroom assessment environment as perceived by the students. Additional validity evidence was obtained through gender differences and correlations of the subscales scores with the total scores received in the subject at end of the semester. Reliability analyses showed that the subscales' scores had relatively moderate levels of internal consistency. Implications and recommendations for classroom instruction and assessment as well as for future research are discussed. Appended to this document is: "Students' Perceptions of the Classroom Assessment Environment Scale." (Contains 2 tables.)