An exploratory study examined teachers' perceptions of students' motivation to read and the relationship between those perceptions and students' reading achievement. Focus groups of third- and fifth-grade teachers were convened and given an initial questionnaire. A second questionnaire based on those findings was developed and field-tested with third- and fifth-grade teachers and students. Questionnaire items clustered conceptually into five categories: involvement, strategies in reading, social, written expression, and persistence. This interwoven series of conceptually cohesive item groupings supported the notion that teachers possess a highly integrated construct of students' motivation to read. Data on students' achievement were also collected and analyzed. For students in grade 5, those perceived by teachers to be highly motivated to read also had high report-card grades in reading and social studies, and students perceived by teachers to be low in motivation to read had low report-card grades in reading and social studies. Across grades 3 and 5, the pattern was stronger: those students perceived by teachers to be highly motivated to read also had high report-card grades in all school subjects; conversely, students perceived by teachers to be unmotivated to read had low report-card grades in all school subjects. No gender differences in students' perceived level of reading motivation or level of achievement were found. (Contains 31 references and 6 tables of data. Appendixes present the initial and revised questionnaires, and data on response choices to the initial questionnaire.) (RS)