This book brings out the benefits and risks of radiation and nuclear power in a simple manner. Beginning with an introduction to the basics of radiation, the book then covers its application in medical diagnostics, cancer treatment, the improvement of agriculture yield, the eradication of pests, and food preservation, its use in non-destructive examination and material characterisation, security devices, its industrial applications in general, and in the petroleum industry and wastewater treatment. Finally, it looks at nuclear power generation. It presents a comparison of nuclear with other energy sources from different angles, bringing out the fact that nuclear power has minimal environmental and health effects. It also looks briefly at the impact of nuclear accidents. The book is written in simple English with frequently asked questions and answers to enable better public understanding. It will also serve as a resource material to graduate students in nuclear science, engineering and medical physics.