This dissertation aims to assess the impact of influence of knowledge management activities on improvement of organizational performances by use of multiple mechanisms, particularly investigating financial effects, but also potential non-financial impacts (for it is believed that they will eventually, over a longer period of time, transform into financial results). The above mentioned is being considered in the context of organizational lifecycle. In the theoretical part of the dissertation the relevant theoretical cognitions from the domain of defining knowledge are identified, considering knowledge a relevant factor for business activities, but also as a (strategic) resource, as well as previous theoretical research of knowledge management. Further on, the organizational performances are being discussed, as well as the potential influence of knowledge management on both non-financial and financial business performances. In the empirical part of the dissertation the following conclusions have been reached: • During the lifecycle of an enterprise the level of development of knowledge management is increased, measured through number of KM activities, systemacy of its application and strategic integration of KM activities. • Level of development of knowledge management elements has a positive influence on non-financial, but not on financial organizational performances. Potential explanation of the above finding can be explained by necessity of a longer time period and a more arranged economic situation, for the conversion of the defined non-financial performances into financial result. • Contrary of our expectations, with the higher lifecycle stage, the intensity of positive impact of development of knowledge management activities on organizational performances does not result. Reason for this could be found in explanation that major part of the examined enterprises are already for a longer period a part of market competition, and therefore tend to refuse to accept new trends in management. Also, Croatian market economy is rather young, and the use of modern management techniques and tools is yet to be introduced with new generations of managers.