This research study has enquired into the circumstances as to when it is appropriate for systemic therapists to use self-disclosure of personal information to their clients as a clinical intervention. Eight experienced systemic therapists were interviewed and the interviews analysed using grounded theory analysis. A wide range in the readiness to self-disclose was found amongst the research participants. This thesis discusses how family/systemic therapy practice and theory have evolved and how this process has affected the development of systemic interventions such as therapist self-disclosure. The systemic literature on the topic of therapist self disclosure is sparse and generally does not differentiate between its uses in different clinical scenarios. It shows that systemic therapy theory has concentrated on the teaching of models and technique while neglecting the development of the therapeutic relationship and interventions such as therapist self-disclosure. The research, supported by the literature, identifies a systemic professional culture that encourages caution in using therapist self-disclosure which has its origins in a number of areas including being overly influenced by Freudian thought and theory The thesis builds on work by Rowan & Jacobs (2002). Their model identified distinct ways of being a therapist which help the therapist to determine the type of therapeutic inventions that are appropriate to be used or not. Three therapist positions were found the instrumental, the fluid and the relational and these are discussed. They are related to four different self-disclosure types that have been identified in the research. Other variables that emerged from the research, in relation to self-disclosure and systemic therapy, are also discussed. The systemic 'self-disclosure framework' has been devised identifying the place of these variables in systemic therapy, with the aim of informing the systemic therapist of their options in their use of self-disclosure. Recommendations are made for systemic clinical practice and theoretical development.