Because of the importance of the elderly in the society and the large number of the world’s elderly population in the work “Attitudes of young people (high school students) towards people in their third age” we researched attitudes of young people among this problem. In the first part of the paper the perception of persons in their third age in society is reflected on, and then basic concepts such as stereotypes, prejudices and, ultimately, ageism are explained. In the empirical part of the paper the level of knowledge of young people about old age and aging, their attitudes towards the persons in their third age and young people's experience of (co)living with persons in their third age were examined. The majority of young people consider people to be old when they are between sixty and sixty-nine years old. The largest proportion of respondents stated that the most required knowledge for people in their third age is that of technology and information literacy followed by physical education, followed by physical exercise, healthy nutrition, followed by social and civic skills. On the other hand, majority of respondents believe that society should provide people in their retirement with the opportunities to acquire new knowledge and skills so that they could continue to actively participate in the life of their community. When examining attitudes about the third age, the majority of respondents agree with the statement that the number and proportion of persons in their third age in Croatia is increasing rapidly while the lowest degree of agreement is with the statement that the care for the persons in their third age takes resources away from the younger population. A statistically significant difference was observed with respect to whether a grandparent lives in a shared household, majority of respondents living in a shared household believing that people in their third age cannot afford a decent life today. Respondents find that society has the greatest influence on creating a negative image of aging and old age. Also, those respondents who stated that they live with their grandparents in the majority point out that the presence of their grandparents enriches their lives and that their grandparents help them in daily life. The results indicate that only few of the respondents visit their grandparents daily, while most of them visit their grandma or grandpa once a week. Service learning with people in their third age in the community was the last part of the survey questionnaire and focused on the experience of volunteering or visiting the Nursing Home and/or the Gerontology Centre. The results indicate that most of respondents have not had such experience so far, which is also a worrying result if we are aware of the benefit of service learning for intergenerational solidarity.