This quantitative study examined novice teachers' perceptions of their principals' most effective instructional leadership practices to ensure a positive school climate. Principals' perceptions were examined to assess their understandings of novice teachers' needs and whether principals have the knowledge to support novice teachers' pedagogical needs. Novice teacher experts (n = 11) and principals (n = 8) participated in a modified Delphi study of three rounds. A three-part instrument, comprised of a survey, Likert scale (Compass Louisiana Leader Performance Evaluation Rubric), and suggestions were used to assess principals' and novice teachers' perceptions. Lawshe's Content Validity Ratio (CVR) measured validity. Novice teacher experts and principals validated 48 IL practices that pertained to classroom management, mentorship, coteaching, communication, lesson modeling, collaboration, data-driven decisions, formal and informal observations, curriculum assessments and school mission. Seven of the 48 IL practices were created from Round One and Round Two of the modified Delphi study by novice teacher experts. Principals may use the results to foster productive and effective school climates that perpetuate novice teacher retention. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]