This book highlights recent advances on in situ gellable hydrogels for drug delivery and tissue engineering systems. It contributes to the development of more effective and targeted treatment strategies for drug delivery and tissue engineering, ultimately leading to improved patient outcomes. The first chapter provides an overview of the status and future directions of in situ gelling hydrogels in drug delivery. The second chapter is dedicated to a general discussion on polymers used to form in situ hydrogels and their mechanism of gel formation. The subsequent chapters are dedicated to exploring the application of in situ gelling technology for targeted drug delivery to specific organs. Information is also provided regarding the role of in situ gelling hydrogels in tissue engineering. This book brings together a panel of highly accomplished experts in the field of in situ gellable hydrogels, discussing the fundamental principles and specific challenges related to drug delivery and tissue engineering applications. The book is targeted at researchers in the healthcare sector, particularly those with backgrounds in polymer chemistry, biochemistry, materials science, biomedical engineering, and pharmacy. It may also serve as a reference material for undergraduate and postgraduate students in biomedical sciences.