The purpose of this study is to determine attitudes held by high school science teachers that would prevent them from utilizing problem-based learning (PBL) as part of their classroom instruction. The scope of the study includes 30 practicing science teachers whose courses have state-mandated, end of course tests. The researcher utilized a mix of both quantitative and qualitative methods, gathering data through attitude questionnaires and interviews; this data demonstrated a relationship between the use of PBL in classroom instruction and the number of years of experience, highest degree held, participation in previous PBL professional development workshops, and use of PBL in the classroom setting. The limitations of this study are the lack of triangulation to support the findings and the need for more in-depth questions specifically pertaining to reasons PBL was not being utilized in the classroom. This research contributes to the larger body of literature on PBL by addressing secondary science teacher attitudes toward this constructivist-teaching model.