This research deals with a particular business organisation model, such as manufacturing cooperatives. The general aim is to analyse the relationship between cooperatives' export behaviour and their size. The specific objectives are twofold: i) to determine whether size is positively related to the cooperatives' export status (exporters versus non-exporters) and ii) to analyse the relevance of size on cooperatives' export intensity. We use data at the Spanish firm-level that covers the period 1991 to 2016. The research confirms that cooperatives' behaviour with respect to exports is similar to that highlighted in the literature for capitalist companies. We have reached an empirical basis for affirming that cooperatives' size significantly influences the decision to export or not to export, but once that step has been taken, the intensity of the exports responds to a plurality of causes, among which the size of the cooperative is not the most important. The results reveal that higher levels of export intensity are positively linked to higher levels of productivity, wages and innovation.