PurposeThe purpose of this paper is to analyze the relationship between Thomas‐Kilmann's Conflict Management Modes (CMM) and Fiedler's Leadership Style (LS) measures, both in the data, and from the theoretical perspective. Based on the conceptual similarities, the authors first propose the existence of a relationship between Thomas‐Kilmann's CMM and Fiedler's LS measures, then establish the presence of the relationship, based on a dataset of Estonian managers.Design/methodology/approachThe authors use a unique dataset of 343 leaders and specialists from different Estonian organizations, on both Thomas‐Kilmann's CMM and Fiedler's Least Preferred Co‐worker test. The data were analyzed by multivariate methods.FindingsThe results indicate that leaders who are task‐oriented, according to Fiedler's model, tend to use more competing as the dominant CMM, while relationship‐oriented leaders are more accommodating. The authors also analyze the effect of individual characteristics, finding that younger managers are more task‐oriented while older ones are typically relationship‐oriented and conflict avoiding; women are more collaborative and less conflict avoiding, and men tend to use the accommodating mode more than women. Surprisingly, women tend to be more competitive.Originality/valueThis is the first study to establish a relationship between Fiedler's Leadership Style and Thomas‐Kilmann's Conflict Mode Instrument. This relationship can potentially be used for assessing the reliability and validity of measurements. The particular shape of it may be used to analyze the links between conflicts, relationships and assertiveness. Additionally, the paper provides an empirical analysis of conflict management habits and leadership styles of Estonian managers.