Revisions to the Caribbean Secondary Education Certificate science syllabuses reflect significant changes to the format of the School-Based Assessment and the process of moderation. The paper explores the professional development needs that these changes may cause. These include planning for teaching and learning, understanding administrative responsibilities and maintaining quality assessment. Assessment for learning is proposed as a suitable framework for supporting the professional development needs of teachers through collaborative activities such as teaming and mentoring. Effective leadership is also necessary to monitor these changes to ensure successful implementation of the changes.