This article focuses on the triangulation of research methods and techniques in the discussion on the evaluation of marketing research. Research traditions in marketing can be referred to the division of research methodologies, according to which the methods of conceptual, theoretical, empirical and formal research is distinguished, based on the use of quantitative methods, mathematical and statistical models. In scientific research on marketing, conceptual methods (i.e. heuristic or creative methods) are used, with a primary focus on the analysis of qualitative aspects of the studied processes, thus making little reference to empirics. The methodology of empirical research in marketing is used to a great extent. It allows developing empirical models, thus making it possible to recognize, e.g. actually implemented models of marketing strategies that may be consistent with or deviate from the theoretical models. However, it should be noted that empirical models do not always have implementation properties, as they most often refer to the present or past reality. Nevertheless, these models may be subject to benchmarking. Moreover, they serve to make conceptual models more probable. For the further development of marketing, it becomes essential to increase the scope of application of formal research methodologies as well. The analysis of the literature indicates the need for an in-depth diagnosis of combined methods in the research process in the broader context of management sciences. The aim of the article is therefore expressed as a research problem in the form of the following question: Is methodological triangulation a prerequisite for research processes in the management sciences? The research results presented in this article are a fragment of complex study on research methodology. Moreover, the conducted empirical research confirms and theoretically proves that methodological triangulation is a necessary condition in research processes. In contrast, verification of developed methods, models or procedures is an essential condition allowing to combine science and management practice, while methodological triangulation supports research processes. Concerning the preceding, the author recommends in the present article to make a scientific effort aimed at elaborating a tool, method or procedure to select proper research methods and techniques for the research process within the scope of management science, with a particular emphasis on factors determining the process quality. Keywords: methods, research techniques, marketing research, triangulation, research methodology