This study examines and classifies the metaphors that twelfth grade students formulated to describe the concept of "learning mathematics". The sample of the study consists of 669 twelfth grade students (317 female, 352 male) of two Anatolian and two vocational high schools located in the city center of Denizli. The following questions guided this study: What metaphors do students use to describe the concept of "learning mathematics"? What conceptual categories can be derived from these metaphorical images? How these conceptual categories differ by high school type? How these conceptual categories differ by students' gender? The data were analyzed both qualitatively and quantitatively. According to the results, 76 valid metaphors and eight main conceptual categories were identified. These main conceptual categories are: discovering an unknown, learning a new skill, solving a puzzle, learning the rules and playing a game, using a tool, difficulties of learning mathematics, pleasure of learning mathematics, having a hardship. According to Pearson chi square calculations Anatolian high school students and girls produced more metaphors about enjoying mathematics than vocational high school students and boys. Also, vocational high school students and boys produced more metaphors about difficulties of learning mathematics and having a hardship than Anatolian high school students and girls.