The thesis of this paper is to demonstrate Plato’s comprehension of beauty, then in due course to describe the relation between art and beauty based on his dialogues, starting with the early interpretation of the aforementioned terms within the dialogue Hippias Major, which contains a few different possible definitions, or rather reflections, of the concept of beauty. The dialogue Symposium is the extension of the dialectical-dialogic reflection initiated in Hippias Major, from which it is possible to perceive the coherence among beauty, truth and good. Furthermore, in one part of the dialogue Theaetetus it is shown in which way the beauty is reachable to human cognizance abilities, and finally on the basis of the dialogue Phaedrus a solution to the predicament of percepting beauty itself is being offered. Also, the mention of the Republic is mandatory, particulary the book X, where Plato criticizes art as an imitation (mimesis).