The functioning of families in emergency departments (EDs) encompasses the level at which the families of older patients perform as a whole during the ED stay. Currently, little is known about how the families of older patients function in EDs. In this study, family functioning included the subareas of family strengths, structural factors and relationships both inside and outside the family. The study aimed to describe family functioning in EDs as evaluated by both the family members (n = 111) of older patients and nurses (n = 93). The data were collected from four Estonian hospitals, and the scale used was the Family Functioning, Health and Social Support scale. The results showed that both the family members and nurses evaluated family functioning and all its subareas as being moderate. Family structural factors were found to be associated with the family members’ social status. The scores in the subareas were higher when older patients had received help from family members before the ED visit. The family members and nurses differed significantly in the scores they gave for family functioning in general and for all the subareas. No association was found between family functioning as rated by nurses and the families’ demographic characteristics. These results suggest that nurses should pay more attention to family functioning in general and to the structural factors within the family, including internal relationships, while older patients are in the ED. Comprehensive knowledge about how families function during an ED stay may help nurses to better meet the needs of older patients and their families and help them to prepare families to provide aftercare at home. Our findings support the idea that healthcare organisation and delivery should be more family centred.