This study seeks to determine the impact of biography-based values education on 4th grade elementary school students' attitudes towards tolerance value. Within the study, an experimental method with pre-test and post-test control group was used to find out the difference between attitudes towards tolerance value adopted by the students of the experimental group in which biography-based values education was practised and by the students of the control group in which it was not practised. In addition, in this study, which includes both quantitative and qualitative techniques, quantitative data were collected through tolerance attitude scale while qualitative data were collected through interview forms. All data collection tools were developed by researchers of the study. In this study, quantitative data were analysed through arithmetic average, frequency, independent samples t-test, Kruskal-Wallis H test and Mann-Whitney U test, while descriptive analysis approach was given preference in the analysis of qualitative data. In this study, researchers drew upon biographies of Prophet Muhammad, Atatürk, Fatih Sultan Mehmet, Haci Bektas Veli, Mevlâna and Yunus Emre. These biographies were presented with the tolerance value and in a manner and a format close to biographical fiction that brings in sub dimensions of the tolerance value including respect, toleration, harmony, flexibility, peace, equality, forgiveness, prejudice, modesty and understanding. In this study, it was determined that after the biography-based values education practice while there was a significant difference in favour of the experimental group between attitude points towards students' tolerance value, there was no significant difference between attitude points of students depending on variables of gender, education and income level of parents. It was concluded from interviews made with teachers, parents and students that the biography-based values education turned out to be a successful practice that concretized the teaching process, catalysed the learning of values, made the teaching environment enjoyable and positively affected students' attitudes towards tolerance values.