In their daily work, social workers are constantly faced with a number of challenges. One of these challenges is working with involuntary clients. This paper will present the main characteristics of involuntary clients through the concept of "actionable knowledge". Involuntary clients are forced to participate in some interventions against their will, while voluntary clients have free choices. The fact that someone is denying them freedom makes them unmotivated for change and prone to resistance. In order to successfully overcome obstacles social workers use “actionable knowledge”, a postmodern concept that refers to specific knowledge that they can use in their interventions with involuntary clients. Some of them are related to values, ethics and communication in social work, establishing collaborative relationships and some of the theories and methods such as reactive resistance theory, transtheoretical model of change and motivational interview model. These findings prove to be very important and useful in achieving client change, allowing solving problems in cooperation of both, social workers and their clients and achieving solution while preserving the uniqueness and dignity of each of them.