This study aimed to investigate the successes and difficulties that teachers perceived as they enacted an argument-based inquiry approach; and instructional strategies that teachers used within an argument-based inquiry approach. Nineteen elementary teachers from 14 Midwestern elementary schools were enrolled in an intensive 2-week professional development program along with 2 follow-up workshops focusing on an argument-based inquiry approach, i.e., the Science Writing Heuristic (SWH) approach. The teachers implemented at least 1 lesson using the SWH approach during the first semester after the 2-week professional development program and a series of lessons for a unit during the second semester. Data collection consisted of teachers' written reflection supplemented by their lesson plans. Data analyses indicated that most teachers viewed students' authentic learning and engagement as the benefits of the argument-based inquiry approach. A majority of the teachers also mentioned students' lack of decision making ability and difficulty of writing their thoughts. Class discussions, scaffolding, and modeling argumentation were used by the participant teachers as instructional strategies as ways to embrace the argument-based inquiry approach in their science classrooms.