Kurt Vonnegut is considered as one of the champion fictional writers of postmodern literature from America. Though he had written a total of 14 novels, SlaughterhouseFive published on 31 March 1969 is regarded as his masterpiece, because of its anti-war narration and pacifistic approach. He is a great philanthropist and anti-war writer of the 20th century. This novel depicts his own war experiences and memoirs during World War II and received good acceptance across the world. Human history had been shaped through war and its atrocities. Various wars and conflicts formed humanity with certain values and ethics. Pacifism is such a quality that opposes war and always promote peace among people and nations. The novel Slaughterhouse-Five depicts the war’s absurdities and atrocities. The major victims of any war are the soldiers, they often suffer a lot during the outbreak of war. This paper mainly focuses on the pacifist approach of the novel Slaughterhouse-Five. Throughout the novel, Vonnegut mocks the stupidities of human beings who are crazy in war. The ultimate result of any war is destruction, and human suffering, Vonnegut does not directly promote and exhorts pacifism in this novel instead he is revealing the stupidities of the war with humour and heartfelt narration.