Carlos Slim is among the most successful entrepreneurs in Mexico. He is also known as the Warren Buffett of Mexico. The aim of this study is to critically analyze and identify the entrepreneurial approaches and psychology that made Carlos Slim the Warren Buffett of Mexico. To achieve this, the Competency theory of Driessen (2005) was deployed. knowledge, capabilities, motivation, and characteristics are the components of competency theory which jointly form entrepreneur competence, which can be interpreted as successful behavior in practice, is adopted and modified to suit the scope of this study. Most of the researches on entrepreneur focused on competency theory as it is deemed suitable for assessing entrepreneur competence, talent, skills, traits, behavior and what characteristics and a motivational factor of entrepreneur influence business success (Laan; Driessen; and Zwart, 2010). Therefore, the theoretical framework for this study was developed using three variables; Characteristics, Capabilities and Internally Driven Motivation, because the variable “Knowledge” can only be assessed on the basis of the business plan which is beyond the scope of this study (Driessen, 2005). The findings of this report show that Carlos Slim has internally driven motivation and need for achievement that propelled him to succeed in business, he also has specialist thinking style, self-belief and risk-taking propensity traits which are the characteristic that enabled him to seize opportunities and to take calculated risk that led to high profitability (Baun and Locke, 2004; Forbes 2010). In addition, Carlos is a creative entrepreneur that can revive any company from the recession and make it profitable at the long run; he is always optimistic and focuses more on the solution rather than the problem (BBC, 2010; Driessen, 2005). These entrepreneur approaches are the factors that contributed to Carlos’ success and made him Warren Buffett of Mexico.