Asar ul Hadees (آثار الحدیث) is a comprehensive two-volume masterwork on the science of Hadees by the renowned Islamic scholar Allama Dr. Khalid Mahmood. This seminal work covers every major aspect of Hadith sciences in a systematic and scholarly manner, making it an essential reference for students, teachers, and scholars of Islamic studies. The book addresses critical topics including the history of Hadees compilation, narrators (Rijal ul Hadees), classification of Hadees, the role of Hadees in Islamic jurisprudence, and a detailed examination of famous Hadees collections. Written in clear and accessible Urdu, it bridges the gap between classical Islamic scholarship and the modern reader. This third edition has been revised and expanded with updated references, new chapters on contemporary issues in Hadees sciences, and improved indexing for ease of research. The two-volume complete set is a must-have for any serious Islamic library.