ABSTRACT Roger Bacon and William of Ockham are notable names in terms of scientific approaches before the Renaissance in Europe. It is thought that their efforts in the path of experimental science prepared the Copernican revolution. The Renaissance period opened the door to modern science for scientists such as Francis Bacon, Kepler, Galileo, and Descartes. Western researchers thought that the rebellion against Aristotelian authority that prevailed in the Middle Ages laid the foundations of modernity and accepted that scientific thought began with an empiricist point of view. But, it is generally overlooked that studies in the Islamic scientific world play a pioneering role in such evaluations. Therefore, the fact that the scientific methodology based on experimentation and criticism was applied long before the modern period in the Islamic World should be revealed through various researches. This study was discussed in order to show that Ibn al-Haytham systematically drew attention to the scientific method in the search for truth and started the search for new alternative models as the locomotive of criticism (şükûk) tradition, long before the modern period. The scientific approach of Ibn al-Haytham was discussed within the frame of methods such as, observation, testing, comparison, criticism, induction, deduction, reviewing premises and principles, relying on evidence, evaluating the results as prejudicefree etc. in terms of theoretical and practical results. Thus, it was concluded that Ibn al-Haytham, who differed from the astronomy and optic scientists before him in terms of his style, technique and method, deserves to be called the “pioneer of the modern scientific approach”.