Nanobiotechnology has been achieved great significance in terms of nanomedicine & many others. But the first challenge in nanobiotechnology science is the preparation of stable nanoparticles. Presently, many preparation methods have been developed like different chemical & physical processes, but the main drawbacks of these processes are required hazardous chemicals, environmental impact, and ultimately expenses a lot. To overcome these challenges another advanced technology has been developed, which is termed green or biogenic synthesis. This review is discussing the modern approaches of the eco-friendly and cost-effective methodology of green synthesis of nanoparticles by using different eukaryotic & prokaryotic agents like plants, human cell lines, diatoms, algae, fungi, bacteria, viruses, and other organisms. Also, this review gives a clear idea of the different applications of those nanoparticles in drug delivery, dentistry, labeling, diagnostics & sensors.