Introduction: Nothing great in the world has been accomplished without passion. Georg Wilhelm Friedrich Hegel (1770-1831) Is passion needed for excellent performance? The question of what predicts outstanding performance at work remains timely and relevant. The term “passion for work” emerged from qualitative research on entrepreneurs’ motivation, and has been defined as a selfish, passionate love for the work (Shane, Locke & Collins, 2003). Passion for work has been proposed as key to understanding entrepreneurial behavior and performance. Passion is “… the enthusiasm, joy, and even zeal that come from the energetic and unflagging pursuit of a worthy, challenging and uplifting purpose” (Smilor, 1997, as cited in Shane at al., 2003). However, few attempts have been made so far as to operationalize the construct, let alone relate it to entrepreneurial behaviour. The current chapter aims to fill this void, by focusing on work engagement and workaholism as two motivational concepts indicating “passion for work”.