Apart from their historical importance, medals are an important symbol of arts for Iranian over the last few centuries. The first important aspect of the medals is their long durability which enables them to carry arts and cultural traditions from many centuries to the Qajar era. The present article deals with the visual study of these developments and by studying the formal, decorative and graphic features of the designs and details of the insignia and commemorative coins of Iran in the Qajar, Pahlavi and Islamic Republic periods, examines art’s and visuals’ changes. A study about these historical artworks is essential due to their visual, decorative, symbolic and conceptual features, which can be classified into two groups including the jewelry and coinage. The medals are important in terms of their artistic style which has been derived from the contemporary Iranian art. The production of medals prospered since the Qajar dynasty that provided a proper condition to study the visual evolution of properties of Iranian medals from the Qajar dynasty until now. A comparative study of medals from the Qajar, Pahlavi and the Islamic Republic can identify the similarities and differences among the various cultures and arts of these periods in the history of Iran. It seems that the symbols and artistic features of each period are influenced by the previous period, but they also reveal the specific differences of that period and according to the political and social differences of each period, there are decorative differences in terms of semiotics with medals of other periods. There is also a gradual change in terms of variety in form, role and symbols used in the medals of these three periods. One of the main goals of this study is to investigate the procedure of visual changes in the medals of honor to understand the depth of Iranian artworks during the three mentioned periods. In this study, we address the following question that “what visual evolution in the medals of honor has occurred from the Qajar to the Pahlavi era and carried to the Islamic Republic period? In addition, what are the visual similarities and differences in Persian artworks during the recent eras?” In this work, an analytical and descriptive method was developed through an extensive literature review as well as Persian museums samples. The visual principles and rules, which were considered to have created the apparent characteristics of medals, were used to analyze the artworks. The statistical population of this study is all government signs made in these three periods. Ten signs from each period have been selected for a more detailed study by random cluster sampling method, so that from each category of signs, related to a topic, several samples were randomly selected and studied, which were then analyzed by related criteria in a logical and deductive way. The method of analyzing the works is based on the study of visual principles and rules, used in the physical characteristics of medals, and based on logical and deductive analysis. In this research, the badges of honor of the three periods of Qajar, Pahlavi and the Islamic Republic are visually studied and compared, respectively. These three periods and the evolution of medals in these periods are discussed. The results of this study showed a more uniform shape and decoration in Qajar medals, which contained remarkable similarities in terms of their title. A special variety in the engraving and decoration of Pahlavi medals was observed, including similar symbols with that of the Islamic Republic. In the Islamic Republic era, diversity in the shape of the medals has appeared in addition to the several engraving and decoration patterns. There are many differences between the symbols of this period and the previous ones. Comparing the medals of the three periods, it can be seen that the Qajar medals were more valuable materially and more expensive jewelry was used in them, with the medals of the Pahlavi and the Islamic Republic eras in the following places, respectively. In the Pahlavi period, the nationalist aspect was more used, while in the Qajar medals more signs related to power and Islamic symbols can be seen. The symbol of the lion and the sun is common in both periods, but is dominant in the Qajar period and is the central image of most medals. Among the symbols of the Islamic Republic, like in the Qajar period, there are many religious symbols. Also, the image of the country's leaders has been portrayed in all three periods. In general, it can be said that Pahlavi medals are more diverse in terms of variety of designs and themes, and Qajar medals are more valuable in terms of material prices and incorporated jewelry, while the medals of the Islamic Republic are comparatively much more diverse in terms of subject matter.