The paper reveals the factors behind the development of trust in the inter-organizational relations of knowledge intensive firms and their implications for building trust in low trust environment. The theoretical framework is based on 5 types of factors: institutional, social, personal, professional and educational. The empirical research was carried out in the Science Park ‘Technopolis’ and covered 14 technological firms. The research has shown that knowledge intensive firms possessed high levels of inter-organizational trust, while at the same time placing emphasis on personal and professional characteristics of their partners, supported by clear contract obligations. They find themselves more vulnerable in their economic transactions than in the knowledge exchange. Trust in business relations of knowledge-intensive firms are primarily based on the professional competence, personal moral qualities of partners, their mutual interest in business transaction and contract obligations. Personal friendships and social concerns play a positive, but secondary role in business transactions. Respondents regard trust primarily as a moral issue, which is based on individual moral qualities. Institutional and educational factors are regarded as key to building high trust on the society level. Empirical findings show that strategies for trust development on inter-organizational and societal levels are likely to be focused on different sets of factors. Professional and personal (some legal) factors play the key role in enabling trust between the knowledge-intensive firms, whereas institutional and educational factors appear to be the key in promoting trust on society level. DOI: http://dx.doi.org/10.5755/j01.ss.78.4.3230