The study aimed at examining the effect of the planetarium trip on metaphors developed by the pre-service science teachers about the concept of planetarium. Within this context of the study, a trip was organized to Ondokuz Mayis University (OMU) Planetarium. Pretest-posttest control group design, one of the experimental designs, was used in the study. Total 64 fourth year pre-service science teachers, 42 females and 22 males, participated in the study. As a result of the study, it was observed that the pre-service teachers in experimental group participated in the planetarium trip and developed metaphors related to the concept of planetarium in a six week process and all of these metaphors changed completely except for one participant. There was no change with the metaphorical perceptions of nearly fifth quarters of the pre-service teachers' in control group in the same time interval. It was determined that the pre-service teachers in experimental and control groups mostly grouped planetariums in the space research centre's category during the pre-interviews.