The subject literature around the world puts a strong emphasis on the discrepancy between the positive attitude towards the idea of sustainability and consumer behaviour. These issues are the subject matter of this paper, which aims at both the identification and evaluation of selected aspects of knowledge, attitudes and eco-friendly behaviour of consumers connected with their choice of foods. The authors made an attempt of answering the question, to what extent do the level of knowledge and the declared eco-friendly attitudes have an impact on specific purchasing decisions. In the empirical observations, the conceptual model of the effects of the environment (knowledge, attitude, behaviour) on the customers' ecological awareness was used. The analysis conducted on the basis of this model indicated that stimulating the demand for ecological products is implemented mainly by the processes of raising awareness, which leads to expanding the consumers’ knowledge concerning ecological farming and eco-friendly foods. In such a way the consumer awareness is built, especially by educational campaigns and promoting/endorsing the ecological foods targeted at young consumers.