The study of values has gained increasing attention in mathematics education as researchers explore ways to improve teaching and learning. This paper presents results from a systematic review of empirical research reported in academic journals on values in mathematics education. The main aim of the study was to explore how the concept of values has evolved over the past ten years, to summarise the trends of prevalent research methods and then to propose a conceptual framework for future research in the area of values. The analysis of 67 peer-reviewed journal articles has identified: three dimensions of defining values-subject, representation, and stability; three main categories of methodologies in the study of values-individual attributes, narratives, and the ways of acting. The findings suggest that future studies could focus on the narratives and the way of acting in researching values in mathematics education, as a way of providing a more comprehensive understanding of how values can be effectively integrated into mathematics education as well as are expressed and put into practice in real-life situations.