Nanotechnology is the understanding and control of matter at dimensions between approximately 1 and 100 nanometers, where unique phenomena enable novel applications. Encompassing nanoscale science, engineering, and technology, nanotechnology involves imaging, measuring, modeling, and manipulating matter at this length scale. Increased energy efficiency, a cleaner environment, more effective medical treatment and improved manufacturing production are just some of the potential benefits of nanotechnology. Biologists, chemists, physicists and engineers are all involved in the study of substances at the nanoscale. Bio-nanotechnology allows the production of new materials and devices including fabrics and cellular engineering scaffolds, molecular motors and biomolecules for the delivery of drugs, sensors of wide spectrum and other medical applications. Nanotechnology offers new engineering tools that can help us address the design problems associated with building better implants. In the context of biomedical engineering, recent technological advancements mean that we now have the ability to manipulate materials with nanometer scale accuracy. This allows us to create biomaterials with features the same size as the proteins and cells with which our implant interact. Nanomaterials may also be used as active sensing elements or receptors, as transducing components (e.g. electro- or chemo-mechanical actuators), and even as electrodes in electronic circuitry and power systems (e.g. nanowires). Developments in this field are taking place at a very high speed. In view of these factors all the developing and developed countries are aspiring to establish strong base for nanotechnology R&D and production. In order to review state-of-the-art research and development in nano-scale phenomenon, devices, systems and manufacturing, the NAM S&T Centre along with the Iranian Research Organization for Science and Technology (IROST), Iranian Nanotechnology Initiative Council (INIC) and IOR-ARC Regional Centre for Science and Technology Transfer (RCSTT) organised an international workshop on 'Nanotechnology-Present Status and Future Prospects in Developing Countries' from 18-20 May 2009 at Kashan, Iran. Scientists from developing and developed countries actively participated in its deliberations. The latest developments in the areas related to nanoscience and nanotechnology were reviewed by well known experts besides presentation of several country reports. This publication includes 21 articles and review papers on various aspects of nanotechnology and would be useful for the nanotechnology researchers, experts and practitioners in this fast emerging field.