Successful trust-relations exist if the trustee reciprocates in accordance with his/her promises to the trustor’s unilateral cooperation. Using a parametric rational choice approach, Coleman shows that an egoist without a moral conscience may place trust in another unmoral egoist. Consequently, successful trust-relations between those actors are possible if strategic considerations play no role for individual decision-making. This paper focusses on such considerations for the emergence of those relations, given complete information (in the sense of common knowledge) of the players. Generally, trust-relations are hard to establish if unmoral egoists take into account their strategic interdependence. It is shown that two different motivations of the trustee, viz., altruism and morality, may suffice to overcome the characteristic conflict between individual rationality and social efficiency in situations with strategically deciding actors.