In Flanders, family foster care is increasingly the option of choice when out-of-home care is needed. However, foster care is a complex and challenging intervention and meeting all expectations by foster parents is frequently hampered by the severity of the mental health problems of foster children and conflicts with birth parents. Moreover, these problems result in high support needs and low satisfaction of foster carers, ultimately leading to placement disruption. This study aims at identifying characteristics of foster children, foster parents and foster placements associated with low satisfaction and high support needs. Support needs and satisfaction from 1216 Flemish foster parents were mapped with the Support Needs and Satisfaction Questionnaire–Foster Parents. Foster parents had rather limited support needs and high satisfaction scores. More behavioural problems of the foster child and shorter time between two visits was associated with more support needs regarding dealing with the birth parents and with support needs regarding parenting the foster child. More behavioural problems of the foster child, less non-professional support and non-kinship care were associated with lower satisfaction. As breakdown and discontinued fostering are linked to dissatisfaction and lack of support, foster placements of children with more behavioural problems, with non-kinship parents and with foster parents with less non-professional support should be considered at-risk placements needing intensive support.