Visualization is important step in problem solving in physics and in this study we focused on only one aspect of that complex process – figure drawing. Figures can have different functions: they can help understand the text, but are not really necessary; they can be an indispensable part of the text containing information; graphs; diagram of forces and other diagrams. This study deals with figures that are not necessary, but can help understand the text and also examines how given figures as well as those drawn by students help in problem solving. The test which was given to participants in this study examines the knowledge and understanding of the law of conservation of energy and some different situations and concepts like energy transformation (gravitational potential, elastic potential and kinetic), work and energy loss. The study was carried out in four different high schools in the city of Zagreb including 240 second class students. The students also filled in a short questionnaire and answered the questions how and in which situations a figure helps them to solve physics problems. In problems without a figure we studied whether students were capable of representing given physical situation on their own and if they were, how informative their figure was. Students generally scored poorly on this test showing a number of difficulties associated with the understanding of the concept of energy and the law of conservation of energy. The analysis of figures shows that a lot of students have difficulties with understanding physical situations or that they do not understand what a completely informative figure means. This study indicated that there is a correlation between figure drawing and success in problem solving. Our results did not show that there is a statistically significant difference in success in problem solving with or without a given figure. However, given figure was not the only indicator of visualization, figures drawn by students were also taken into consideration. The students who were not given a figure and did not draw one themselves achieved lower success than the students who were given a figure or drew it themselves, which indicates that visualization significantly influences the results in problem solving. Also, students who drew more accurate and complete figures achieved better results. This study shows that drawing figures as a form of visualization of a physical situation does help in problem solving. Teachers should encourage their students to visualize and draw physical situations.