This book is a sincere attempt by the authors to give a comprehensive account on the chemistry of hydroxamic acids, poly (hydroxamic) acids and their metal chelate polymers. This book highlights the different applications of hydroxamic acids, poly (hydroxamic) acids and their metal chelate polymers in different fields of chemistry. A detailed account on the coordination chemistry of these compounds has been incorporated in this book. A comprehensive review of literature has also been included in this book. The present book incorporates experimental procedures for synthesizing hydroxamic acids, poly (hydroxamic) acids and their metal chelate polymers. One of the chapter of this book deals with the characterization of synthesized compounds by different techniques like IR, 1H-NMR, Electronic spectroscopy.The fourth chapter of this book deals a detailed account on antimicrobial studies of synthesized compounds on Pseudomonas aeruginosa bacteria and Aspergillus awamori fungi with a view to search of good antimicrobial agents. Increasing knowledge of the biological activities of compounds may guide to many researchers to develop the promising chemotherapeutic agents.