The purpose of this study is to determine perceptions of elementary prospective teachers about the basic concepts of physics including force, motion, speed, velocity, acceleration and displacement. This research, as a qualitative study, had a study group that constitutes of 35 elementary prospective teachers who successfully completed general physics courses. A word association test was used as the data collection tool. In the word association test, elementary prospective teachers were asked to write down the first five words/concepts they thought of regarding the concepts of "force", "motion", "speed", "velocity", "acceleration" and "displacement" in the first stage, in the second stage they have been asked to write the sentences regarding these concepts. A frequency table was formed with the words/concepts that the prospective teachers associated with the key concepts, cutoff points were determined based on these data, and conceptual networks that reflected their perceptions were drawn. Prospective teachers' sentences for key concepts were analyzed by using content analysis method. The findings showed that the participants associated the key concepts mostly with the concepts of distance, time, velocity, force, energy, motion, friction, power, car, physics, displacement, acceleration and speed. Additionally, it was observed that a significant part of the sentences formed by the participants was scientifically acceptable, while the participants also formed similar sentences that contained emotional and unscientific expressions.