Abstract. The article presents methodology and results of a psycholinguistic experiment. The experiment was conducted with the purpose to figure out the meanings, structure and prototypes of the category «musical instruments» in the conceptosphere of ordinary speakers of Polish language. The experiment consists of three parts. When designing the experiment we considered that when preserving the cognitive image of musical instruments humans use different ways of encoding information (audial, visual and verbal). Respectively, our experiment was directed onto the three abovementioned forms of fixation of information about musical instruments. The first part of the experiment was directed onto investigation of the verbal information, the second – onto visual and verbal and the third part was designed to find out about audial and verbal information that is connected with the images of musical instruments. There were 77 respondents, none of them studying music as their major; all the participants are the students of Maria Curie-Skłodowska University, Lublin, Poland. The investigation shows that the nucleus of the category is made up by guitar, violin and piano, whilst organ, flute and tambourine are included into close periphery.