Objective: This research investigated teachers' perceptions of the impact of professional development on the classroom instruction of secondary business teachers and the relationship between the impact of professional development and the number of hours spent in professional development. Background: Quality professional development for teachers can improve students learning. Research shows that more teacher skill and content knowledge translate into increased student achievement. Method: Descriptive and correlational research methods were used. Participants included 109 secondary business educators in one state who were asked to complete an online survey about the perceived impact professional development had on their classroom instruction and how many hours they spent in individual professional development during a 12-month time period. Results: Impact on instruction was considered positive since the average score of 118 reflected a modest agreement with impact statements. No significant correlation was found between the impact of professional development on instruction and the number of hours spent in professional development. Conclusion: Teachers revealed an overall satisfied attitude with the instructional impact professional development produced; however, more hours in professional development did not automatically translate into a perceived greater impact on instruction. Application: Professional development offerings should be carefully selected by the administrator and the teacher based on the needs of the teacher and his/her students. (Contains 1 figure and 2 tables.)