ABSTRACT Counselors at a public community college who teach a first-year college success course to developmental education students do not have effective opportunities or a systematic method to develop their teaching practice. Moreover, like a majority of community college and university instructors, many counselors do not have formal training in instruction. Since the retention and persistence rates of developmental education students are low when compared to non-developmental education students, and the purpose of the college success course is to increase developmental education student success, it is imperative that instructors of the college success course are well-trained to provide high quality learning experiences. The researcher implemented the Lesson Study (LS) professional learning experience in order to increase the collaboration amongst counselors in their efforts to improve their teaching practice as well as improve the quality of the learning experience for developmental education students, consequently potentially improving their retention and persistence. The researcher facilitated a mixed-method study to explore how instructors made meaning of their teaching practice as well as what changes they made to their instructional practice while engaging in LS. The researcher utilized qualitative means to analyze the following data: (1) instructors' weekly reflective journals, (2) semi-structured interviews with instructors after each cycle of LS, (3) video recordings of LS debrief meetings, and (4) video recordings of LS planning meetings. The researcher utilized quantitative means to analyze the following data: (1) pre/post instructor surveys on self-efficacy, and (2) 1,235 student questionnaires regarding LS lessons and non-LS lessons. Analysis of the qualitative data demonstrated that how counselors made meaning of their LS experience seemed to correlate with positive features attributed to the practice of LS in the research literature such as increased collaboration and in-depth reflection as well as positive changes in instructional practices and an increased focus on learning from practice. In addition, analysis of the qualitative and quantitative data showed that lessons created through LS produced a higher quality learning experience for students than lessons that were not created through LS. Moreover, the analysis of the data showed an increase in instructors' efficacy for teaching.