This paper examines some of the main processes in the evolution of triangulation in qualitative research (QR) and social representations theory (SRT) in social psychology in recent decades. By adopting a cross-historical approach, we seek to outline how SRT can strengthen its epistemological approach by embracing triangulation, and to highlight that an examination of past and current debates on SRT can provide relevant insights for QR in psychology. We show how, progressively over time, in both fields (SRT and QR), discrepancies between data obtained by different methods were no longer considered a threat to scientific validity of the data but as a way to deepen understanding of the phenomenon being studied. Thus, developing systematic triangulation, which combines the various epistemological, theoretical, and methodological backgrounds of different methods (data collection and/or analysis), enables SRT to fulfill its potential even more in contributing to a societal social psychology. Reciprocally, SRT provides a framework in which QR can develop some of its full potential, for example, in the areas of multi-method studies, multidisciplinarity, and engagement with social change.