The ongoing changes in the modern world - represented with nano-, bio-, info- and cognitive technological development - requires a certain skill set, mastering of which is necessary for any professional and above all - a STEM-specialist. Thus, alongside the technological advancement, leading global corporations seek to employ candidates exhibiting particular soft-skills, among which leadership and emotional intellect are in especially high demand. The purpose of the article is to formulate a comprehensive STEM portfolio, consisting of soft, emotional and leadership skills (SELS). Consequently, a new method of developing leadership skills in the STEM educational process is offered. As opposed to traditional methods of management, the new approach is based on the principle of emotional intellect, thus allowing to influence employees on a level that engages them personally, hence more effectively. The offered methodology is applicable in both educational and corporate spheres of professional STEM activity. © 2020, Kassel University Press GmbH.