The professional teaching and learning cycle (PTLC) is a professional development process in which teachers collaboratively plan and implement lessons aligned to their state standards. This process is an important part of the Working Systemically approach, designed by SEDL to improve a school system's capacity to increase student achievement. Working in partnership with the Charles A. Dana Center at the University of Texas at Austin, SEDL developed this job-embedded process that reflects the research on professional development and school improvement. PTLC is an ongoing, cyclic process that is designed to improve the: (1) quality of professional development (ongoing, job-embedded, results-driven); (2) professional collaboration among staff; (3) use of data to inform instructional and programmatic decisions; (4) alignment of curriculum, instruction, and assessment to the state standards; (5) quality and coherence of instruction across classrooms; (6) monitoring of student learning; and (7) leadership-support systems for continuous school improvement. The process comprises six steps--study, select, plan, implement, analyze, and adjust. This publication provides a detailed overview of the process and outlines the objectives for each of the six steps and the overall cycle. It also addresses the importance of leadership roles and the culture and conditions necessary to support PTLC. The information presented herein provides the grounding needed in order to understand and explain PTLC to teachers and leaders as they work through this process.