The presented paper discusses problems of small businesses economic co-operation defined as the establishment of lasting relationships and links between firms which do not represent typical market transactions. Particular attention was paid to specific interactions resulting from the occurrence of certain features distinguishing small firms from other market players. On the basis of available literature the following characteristics, differentiating interaction, were selected: the combination of an entrepreneur with the company and the owner/manager with the family. The first two characteristics determine the way of conducting business activities owing to personal characteristics of owner/manager who creates the specific organizational culture or has certain reasons for taking decisions about the company development. Attention was also paid to an important aspect, appreciated by entrepreneurs, namely financial and economic independence which affects the choice of economic cooperation forms. The knowledge of local market at which the company operates also constitutes an important attribute, as well as the network of personal contacts, which depending on an entrepreneur's experience may facilitate the establishment of cooperative relationships. The presented characteristics are revealed in the context of small businesses interaction analysis with other market operators distinguished on the basis of size. Empirical research shows that it is possible to extract characteristics of small-businesses interactions with other young and small to medium-sized and large companies. These first relationships are characterized by easy access to decision-makers, lack of communication barriers and cross-matching offer which results in both parties satisfaction. Negative aspects refer mainly to poor offer parameters which bring about minor financial benefit. Good commercial conditions and access to knowledge about new technologies, products and the absence or limited access to decision-makers and poor communication constitute the most important features of interaction between small enterprises and large as well as medium sized ones. The research illustrates that small businesses more easily interact with other small businesses, but if medium and large enterprises improve communication and accessibility of policymakers, then small businesses would prefer to interact with such entities at the market.