Education researchers regularly seek to evaluate and define what encompasses successful professional development (PD) for teachers. Numerous items and lists that are considered the characteristics of "effective PD have emerged from this research." However, follow-up with teachers on their perceived views of these characteristics is lacking from the literature. Teachers can help determine which aspects should be considered in the design of high-quality professional learning in the future. For this study, Q methodology was utilized to examine the subjective views of the teachers. Q sorts were correlated and factor analyzed (PCA with cluster rotation) to extract four significant factors on which all 17 participants loaded significantly (McKeown &Thomas, 2013; Newman & Ramlo, 2010; Watts & Stenner, 2012). These factors were examined through the lens of andragogy (adult learning theory) to determine the connections between the characteristics of effective PD and the core adult learning principles. Teachers in this study perceived effective PD as those opportunities that establish cooperative learning amongst participants, focus on improved student learning outcomes, provide opportunities for feedback, and allow for ongoing support. Future research is needed to see if the results obtained apply to other teacher populations.