The article elucidates the findings of a theoretical and empirical study of the decisiveness features of the individuals who differ in their emotional disposition. The study is of great scientific importance in view of the social and cultural transformations in modern society, which demand an individual's ability to make choices in the utterly difficult situations of social instability. The scientific approach to the development of this issue implies the search for psychological resources, indicators of decisiveness, and the study of its individual-typological features of people with different emotional disposition, and subsequently, those with disorders in the emotional sphere. The study approaches decisiveness as a complex, integral personality trait that ensures successful decision-making. The decisiveness pattern embraces several blocks of indicators: a block of setting indicators, a block of psychophysiological indicators, a block of cognition indicators, a block of the personality-related components of decisiveness. Certain qualitative and quantitative combinations of these indicators correlate with the individual psychological features of decisiveness. Emotionality is chosen as the basis for finding out individual differences of decisiveness since psychology interprets it as one of the dominant characteristics of humans, along with the mental activity. The diagnosing of decisiveness components was carried out using an original methodology of the Multidimensional Scale of Decision-Making, while emotionality was studied on the basis of the Psychodiagnostic Four-Modality Emotionality Test-Questionnaire. The study has revealed that emotionality has a systemic influence on the individual psychological structure of decisiveness. The key findings indicate that, depending on the type of emotionality, decisiveness acquires individual specificity, which manifests itself in a unique qualitative-quantitative combination of its multilevel indicators. The article seeks to substantiate the uniqueness of the individual-psychological features of decisiveness, presenting them as a multi-component integral property of personality.