This book contains four chapters reviewing hydrazine and its applications. Chapter One overviews derivatives of hydrazine as massive sources of pharmaceutically bioactive drugs. Chapter Two looks to hydrazine derivatives such as pyrazole, pyridazine, etc as a source of pharmaceutically bioactive drugs. Chapter Three explores the use of carbon based nanomaterials for the electrochemical determination of hydrazine. Chapter Four reviews a nano-composite materials approach to hydrazine detection.