Purpose The purpose of this paper is to illustrate and discuss methodology issues in menu-labelling experiments in commercial full-service restaurants, and to investigate how the menu description and price affects customers’ choice of an organic veal entrée in a Norwegian restaurant. Design/methodology/approach A menu-labelling experiment was conducted in a fine-dining restaurant during ordinary opening hours over a period of two weeks. The menu description of an organic veal entrée was altered repeatedly and the effect of these changes on the sales of this entrée was investigated. Findings Adding words to the menu description, such as “organic”, or describing animal welfare had a very limited effect on customers’ choices in the restaurant. Research limitations/implications The research illustrates the use of a natural field experiment in a commercial full-service restaurant and discusses strengths and weaknesses of the methodology. Originality/value Few experiments have been performed on the effect on credence attributes in commercial full-service restaurants and there is little knowledge about research challenges in menu-labelling experiments. This paper contributes to the knowledge on both issues by conducting a natural field experiment in a fine-dining restaurant.