The present article presents a classification of the types of knowledge and their importance for a company's competitiveness. The quick access to, transfer and generation of knowledge are extremely important for an organization to become a leader. Some Bulgarian organizations (banks, lawyers, insurance, consultant and software companies) have been studied to establish their key knowledge in four aspects: functional, cultural, positional and regulatory capabilities. The inquiries were performed on-line and in situ. The results have been analyzed and represented graphically. Depending on business activity interviewees estimate different elements from each group. For most of them this was the first study aimed at determining the most valuable knowledge in the organization and its relation to competitive advantages. In most Bulgarian organizations strategic planning is carried out mainly by the management and involves basically financial, technological and market aspects. Further training and research are necessary to recognize the role of intangible assets to improve performance of Bulgarian companies.