This case study reports the effects of a cooperative learning field experience on a pre-service teacher's views of inquiry-based science and her science teaching self-efficacy. Framed by an action research model, this study examined (a) the pre-service teacher's developing understanding of inquiry-based science teaching and learning throughout the planning and implementation phases of the field experience and (b) the pre-service teacher's inquiry-based science teaching self-efficacy beliefs prior to and after the field experience. The pre-service teacher's self-reflections before and after the field experience, video reflections, and results from the Personal Science Teaching Efficacy, a subscale on the Science Teaching Expectancy Belief Instrument-form B, were analyzed in this study. The findings revealed that (a) the pre-service teacher's understanding of inquiry-based science teaching and learning was developed and enhanced through the planning and teaching phases of the field experience and (b) the pre-service teacher's science teaching self-efficacy beliefs were improved as a result of a stronger appreciation and understanding of inquiry-based science teaching and learning. Further, the significance of this study suggests the use of cooperative inquiry-based field experiences and pre-service teacher action research by teacher education programs as means to deepening understanding of inquiry-based science instruction and increasing self-efficacy for such teaching.