Public Private Partnerships (PPP) have been much discussed throughout Europe, but does the practice match the idea of cooperating actors who achieve added value together and share risks? An analysis of three cases of PPP in The Netherlands suggests that practice tends to be less ideal than the idea. Actors have difficulties in achieving actual joint decision-making and organisation and tend to organise their interactions in a traditional way: by contracting out and by separating responsibilities. From a network perspective we will analyse the actor constellations around urban investment projects in which the use of PPP is discussed and elaborated. We will identify their institutional characteristics and the behavioural logic used by public and private actors. Despite the presence of a great many good intentions, institutional factors prevent parties from achieving actual partnerships. Because these factors (i.e. role attitudes, behavioural rules, perceptions (of each other)) cannot easily be changed – i.e. they cannot be changed by just one or two managers, but must become part of the culture within the actor constellations – there is still a long way to go before the idea of partner-ship is transformed into actual practice.