Recently the question of eco-labelling has become increasingly important, especially when used as a green marketing tool. Surprisingly, the marketing placebo effect of eco-labelling and the influence it has on the performance of a product has received little attention. The purpose of this study is to explain the placebo effect of eco-labelling on consumer attitudes. Fishbein’s model of attitudes is implemented whereby a focus group is used as a basis to create a questionnaire and a tasting experiment. The findings of the study provide an explanation and evidence of the placebo effect of eco-labelling. The product with an environmental label is perceived as tastier, healthier and of higher quality than the same product without ecological label.