This paper presents an analysis of resistance to change in family therapy — a concept central to the understanding of drop-outs. The resistances used were categorized as Resistance to Therapy, Resistance to Interaction and Family Specific Resistances. Family behaviour was conceptualized as governed by homeodynamic patterns, self-reinforcing modes of interaction in which the primary emphasis is on the preservation of stability. Five families who dropped out of therapy after up to 17 sessions were described in detail. They had consulted for psychiatric symptoms presented by one or more children, and were treated by the author in weekly conjoint family sessions. The dynamic interplay of resistance and change was apparent in all five cases where family members resisted working through the marital conflict, and disrupted treatment when imminent change in the husband-wife relationship was perceived as a threat to family stability. The discussion dealt with the crucial role of the parental couple's strengths and weaknesses as a prognostic indicator, the importance of re-assessing treatment goals after the family is fully engaged in therapy, and the role of the therapist in provoking drop-out. In addition, the drop-outs were compared to families who remained in therapy.