The main purpose of this doctoral dissertation is to examine the growth and development process of already established small and medium-sized enterprises (SMEs). The process is examined by defining the correlation between change management and strategic development of SMEs in terms of maintaining dynamic balance between organizational effectiveness and efficacy with the purpose of more successful strategic adaptation measured by company performance. The main goals of the study are to: determine the main characteristics of change management, strategic development, performance and surroundings of small and mediumsized enterprises in the Republic of Croatia, determine whether there are differences in relation to the potential (fast-growing, high-tech and innovative), analyze the causal connection among the key concepts and examine the importance of differences and the connection between the key concepts and variables in surroundings. A conceptual model was formed on the basis of theoretical research. The results of the empirical research are based on the sample of 190 established SMEs. The results indicate the following: a) more conspicuous characteristics of enterprises with the potential in the area of organizational and strategic dynamics, and related assessed performance, b) empirical confirmation that SMEs in which a higher level of individual orientation of entrepreneurs towards change, an increased level of a planned approach to change, increased flexibility of human resources and a higher level of organizational ambidexterity have a higher level of strategic dynamics, c) empirical confirmation that SMEs that have a higher level of strategic ambidexterity, strategic flexibility and diversity and strategic orientation deliver a higher level of performance, d) empirical confirmation of the connection between special characteristics of SMEs and the characteristics of their organizational dynamics, and e) empirical confirmation of the connection between the intensity of insecurity in the SMEs surroundings and characteristics of their organizational dynamics. This doctoral dissertation contributes to the explanation of growth and development of already established SMEs in theoretical and empirical context. The results of the study in the area of better understanding of the role and dimension of organizational and strategic dynamics with the aim of growth and development of SMEs could help the development of appropriate measures of institutional support. There are several limitations of the study that should be taken into consideration when generalizing the results: a limited number of variables collected in the study, the size and heterogeneity of samples, the recessionary context of the study, an on-line questionnaire and its length, and inability to draw a comparison with similar studies