Nanotechnology is a new innovative scientific field with great potential benefits for society but also with environmental risks. Expert stakeholders have an important role in assessing these benefits and risks associated with nanotechnology and translating their knowledge to society. Their opinion may have an important influence on both public opinion and policies. The aims of the present study are to investigate expert stakeholders’ attitude toward nanotechnology and nanomaterials and their attitudes towards a stronger regulation of this technology. A web-based survey distributed to 237 individual Swedish expert stakeholders shows that experts in general favors stronger regulation. Their attitude to regulation is influenced by their self-rated knowledge of nanotechnology, ethical considerations, perceived benefits and risks with nanotechnology but also the importance of nanotechnology for their own organization. Experts working in authorities are more in favor of stronger regulations than experts in businesses. Although experts in authorities and business shares fairly similar views on risks and benefits with nanomaterials and technology their attitude towards regulation are partly influenced by different determinants. While experts in authorities’ attitudes toward regulation are influenced by perceived benefits with the technology and not perceived risks, it is the other way around for experts in businesses.