The implementation and use of organizational innovations is seen as one of the key success factors for enterprises, nowadays. Regardless its importance, which most researchers of this field agree on, only little is known about this topic. This thesis wants to contribute to the knowledge about organizational innovation. An own definition for the most important characteristics of organizational innovations has been formulated. This thesis features a list of a number of organizational innovations, which are parted in the three categories processes, management methods and organizational structures, which have been identified during the research. As one of the biggest blank spots in the literature, the diffusion of organizational innovations has been identified. In order to learn if a pattern in the diffusion process of organizational innovation exists, five case studies have been built. The bulk of the data for these case studies originate from two surveys, which have been carried out in the course of this research. As participants Austria's 500 most successful companies, as well as Austria's members of the AEC industry have been chosen. The research revealed, that in four out of five cases a logistic function was the right approach for the creation of a saturation model for the diffusion processes. The fifth diffusion process followed the model of exponential growth, which can be explained by the fact that the process finds itself in a very early stage of the overall diffusion process. This results in the learning that diffusion processes of organizational innovations are following the same pattern as the diffusion processes of product innovations, which are more present in the existing literature.