Children placed in foster care families usually continue to see their birth parents in supervised and home visits. These children deal with the fact that they belonged to two families in a context where the relationship between the two families is sometimes complex and tense. Based on 45 semi‐structured interviews conducted with foster care families and kinship foster care families, the present study examines the relationship between foster care parents and birth parents in a placement context, and focuses on the factors affecting the nature and quality of this relationship. The results showed that the quality of the relationship dynamics varies according to the following: how well and how often the parent–child visits took place, the birth parents' characteristics, and the foster carers' attitudes. The results also showed that placements in kinship foster care families were more likely to result in conflict and tension between the two parties than placements in regular foster care families.