Early adolescence is a critical time for examining academic motivation, specifically motivation to read (Hervey, 2013). In order to support self-determined motivation to read, students’ needs for competence, autonomy, and relatedness must be met within the classroom context (Miller & Faircloth, 2014). Since classroom instructional practices are a key component of adolescents’ daily experiences in the classroom, research which investigates the influence of these practices on students’ self-determined motivation to read is needed. In addition, the perceptions of students and teachers regarding the degree to which classroom instructional practices meet students’ needs as well as the influence of classroom instructional practices on students’ self-determined motivation to read must be considered as the perceptions of these two groups of classroom stakeholders rarely fully converge (Delaney et al., 2014; Wang & Eccles, 2014). However, the field is lacking an established measure of both groups’ perceptions of classroom instructional practices and the degree to which they support students’ needs (i.e., competence, autonomy, relatedness) and self-determined (intrinsic) motivation to read. Therefore, this study sought to address this gap in the literature by developing and validating a measure with parallel teacher and student forms called the Language Arts Reading Practices Survey (LARPS). This measure assessed student and teacher perceptions of the degree to which classroom instructional practices in the language arts classroom support students’ needs for competence, autonomy, relatedness, and students’ self-determined motivation to read. The results of this study provide preliminary support for the validity of the student form of the LARPS, with less support for the teacher form of the measure. By assessing both student and teacher perceptions, the LARPS adds to the general understanding of specific instructional practices and how stakeholder groups view these practices regarding their ability to support students’ needs and motivation.