This paper investigates psychological and ethical hedonism in Oscar Wilde's (1854-1900) The Picture of Dorian Gray (1891), as an unsatisfying method of living. This philosophy has been recommended as the way of finding the best way to happiness and a good life. From the first day of the history of human’s existence to the present time, ‘pleasure’ has been one of the highest goals, and what has given form to human's behavior. Pleasure is the indispensable principle of the philosophy of Hedonism. Wilde was an intelligent Irish writer, poet, essayist, dandy, playwright, novelist, and epigrammatist. The Picture of Dorian Gray, as a dark, sardonic, gothic and supernatural novel, was the topic of much controversy at time. The novel is one of the best examples of hedonism which shows the start of seeking, and experiencing kinds of pleasure; moreover, it offers some outcomes of using it in the most artistic and aesthetic way. This paper will discuss the smooth transformation of the protagonist in details. Wilde designated hedonism in The Picture of Dorian Gray, by injecting the idea of seeking pleasure into the protagonist's mind and life. Dorian Gray follows hedonism and gives freedom to all his desires, and seeks any kind of pleasure. Accordingly the outcome of living a pleasure-based life would be the subject of considerable thinking and discussion.