We will describe two fundamental concepts of modern Organisational Psychology, offering an experimental model to support our hypotheses. We will start our analysis from the concept of Psychological Capital, understood not only as personal psychological baggage but also as a means for the expression of individuality. The formulation and analysis of the concept of PsyCap (Luthans & Youssef, 2004) will guide our path to the consideration of performance as an expression of Psychological Capital. We will then move on to the analysis of the concept of Work Satisfaction in a framework in which the man-work relationship can represent an opportunity for personal growth through the contextualized expression of one's own abilities. Particular attention will be paid to the analysis of the intrinsic and extrinsic variables of the construct. We will then present a research on Sustainable Working Well-being (BLS) analysing in a particular way the constructs and dimensions related to PsyCap and Work Satisfaction, to conclude by offering a synthesis of the various themes addressed, with particular reference to the relationships between constructs.