A study examined (1) whether students whose teachers possess a higher level of professional development exhibit greater time-on-task in reading than students whose teachers exhibit a lower level of professional development, and (2) if any specific aspects of teachers' professional development were related to a significantly greater amount of time-on-task in reading on the part of students. Data describing teachers' professional development were collected from 35 classroom teachers on personal data forms, while time-on-task data were collected by observing 200 individual students in four elementary schools at periodic intervals during the school year. Findings indicated there was no relationship between average student time-on-task in reading and four of the five aspects of teachers' professional development investigated. One variable, possession of a Master's degree, was negatively associated with student time-on-task at a statistically significant level. Finally, a significant negative correlation was found between years of teaching experience and student time-on-task, suggesting that as teachers acquire additional teaching experience their students exhibit a decrease in time-on-task in reading. (Tables of data and a five-page bibliography are included; among the appendixes are the classroom observation form, teacher personal data form, project guidelines, and teacher time allocation form.) (Author/HOD)