One’s personality affects how he/she processes information and makes decisions. There are various personality models in behavioral finance that can be used in identifying individuals' talents in investment decisions and also in defining the characteristics of shareholders in these decisions. The present study aims to identify key behavioral factors affecting investors' decisions and evaluate these factors based on the Keirsey’s temperament model (1984) using fuzzy multi-criteria decision-making techniques. First, the most important components and indicators were extracted using library studies and reliable sources. Then, the evaluation components and indicators were identified using semi-structured interviews with complete count sampling method of 50 experts and specialists in the field of investment. The findings of the research in the Delphi-fuzzy technique detected 34 indicators in 7 main factors: financial literacy and management, risk perception and behavior, emotions, materialism, debt, money value, savings and investment. The results of the fuzzy-deterministic technique indicate that the debt factor is considered as the cause and the rest of the factors are considered as the effect. In the fuzzy-AHP technique, the artisan has the highest value in the emotion factor. For the guardian temperament, the literacy and financial management factor has the highest value. In the idealist temperament, the savings and investment factor and in the rational temperament, the risk perception and behavior showed the highest value. In the fuzzy-TOPSIS technique, the rational temperament has the highest value in the personality ranking in investor decisions.