This article investigates the image of an ideal foster grandparent as constructed by social workers, drawing upon 24 in-depth interviews with practitioners from foster care agencies in the Czech Republic. Social workers are central to the formulation and delivery of interventions with foster families, and understanding their expectations of foster care provided by grandparents is crucial to understanding services for foster children. The findings, contextualized within legislative, historical, and sociocultural frameworks, reveal three related expectations: the ideal foster grandparent is not a parent to their child, is not a grandparent to their grandchild, and serves as a therapeutic caregiver. Examining these expectations highlights the need for reflection and supervision to minimize potential biases in social work practice, as well as the importance of developing grandparent-specific interventions to address the unique dynamics and challenges of such care.