This paper gives an empirical contribution to the debate on neworganisational forms, complementarities and their relation to a firm’s competitiveness by means of a study on the organisational evolution of Micro/Small Enterprises (MSEs), which represent more than 90% of European firms but are not yet well analysed from the organisational point of view.This paper, based on a survey on a sample of 147 Italian MSEs, investigates firstly the diffusion of a set of organisational and technological innovations.Secondly, the question is asked whether entrepreneurs invest in only one type of innovation or if there is a simultaneous adoption of coherent set of innovations. Finally, the relationship between the adoption of a system of innovations and the dynamic of firm’s performance measured by sales and product innovation is investigated.