Over the last decades there is a growing body of literature on how to enhance farmers' participation in voluntary subsidised agri-environmental programmes. However, additional unsubsidised agri-environmental measures that farmers perform are often ignored. The willingness to perform these measures may give a better insight into farmers' motivation for agri-environmental measures than subsidised measures because it likely depends only on farmers' intrinsic motivation and not on extrinsic factors such as a financial compensation. In this study we used an extended version of the Theory of Planned Behaviour (TPB) to investigate which factors are associated with farmers' intention to perform unsubsidised agri-environmental measures. Our results demonstrate that attitude, perceived social norms and perceived personal ability are significantly associated with farmers' intention to perform these measures. However, self-identity is the most dominant predictor of farmers' intentions. Furthermore we found that Environmental Cooperatives (ECs) positively influence farmers' willingness to perform additional unsubsidised measures by means of facilitation and group pressure. We conclude that in order to increase farmers' willingness to perform agri-environmental measures, self-identity should be addressed by means of e.g. benchmarking instruments in combination with commitment making or labelling of environmental friendly identities. Also, ECs are more important for unsubsidised measures than previously assumed - we recommended that they change their focus to include unsubsidised as well as subsidised conservation. (C) 2016 Elsevier Ltd. All rights reserved.