This book gives a complete overview of current developments in the fabrication and diverse applications of metal and metal oxide nanomaterials synthesized from agricultural/horticultural products and organic waste materials. Nanoparticles are thought to have been present on earth naturally since its origin in the form of soil, water, volcanic dust, and minerals. Besides their natural origin, they have been also synthesized by using physical, chemical, and biological means. The chapters in this book look at agricultural as well as horticultural wastes from industries, such as palm oil, rubber, paper, wood, vegetable, coffee/tea, rice, wheat, maize, grass, and fruit juice processing factories, and describe the methods to extract and synthesize metal and metal oxide nanoparticles, which are then applied in various sectors such as food, agriculture, cosmetics, and medicines industries. The book is a reference source for academician, scientists, policymakers, students, and researchers scientist working in minimizing the environmental pollution and implementing nanotechnology into agricultural waste products to produce eco-friendly and cost-effective nanoparticles.