Professional development is a vehicle through which teachers enhance knowledge and skills that can lead to school improvement and increase student achievement. Action research, a prevalent form of professional development, considers the characteristics of effective professional development and supports adult learning. Designed by the teacher and focused on specific classroom needs, action research encourages teachers to study their own pedagogy, to look critically and analytically at their work, to discover what is effective, and to improve classroom practice (Mills, 2007). This quantitative case study examined teachers' attitudes about action research and the extent to which their attitudes were affected by their age, gender, teaching experience, level taught, subject taught and educational attainment. The examined teachers' attitudes about action research were then compared to their attitudes about other forms of professional development (e.g., workshops, conferences). Finally, teachers' self-reported intentions to implement action research were examined and the extent to which their intentions were influenced their age, gender, teaching experience, level taught, subject taught and educational attainment. Overall, high school and elementary teachers indicated that conferences were the most effective form of professional development. Middle school teachers indicated that education courses at a college or university was the most effective form of professional development. From the analysis it appears that teachers enjoy the professional development opportunities that they are already receiving. They prefer events, single-session workshops and rate longer professional development experiences less. Although once attempted, action research became the most effective form of professional development. The regression showed that higher action research attitudes are present among teachers that have a positive attitude toward professional development and that teaching level is a significant factor contributing to attitude. The results of this case study provide a strong argument for making changes to current practices regarding professional development opportunities provided for secondary teachers. Providing more relevant professional development opportunities for secondary teachers, specifically teachers of science and social studies would prove to be beneficial. Professional developers should think about specific populations of teachers and design purposeful programming directed towards these groups.