José María Postigo, 54, and Rosa Pich, 49, from Barcelona always dreamt of having a large family, but have had to overcome some serious struggles to make their dream a reality.
The family, who have the most school-age children in Spain "and possibly Europe" were chosen by the European Large Families Confederation (ELFAC) as Europe's Large Family of the Year, and received the award from Spain's Health Minister, Alfonso Alonso on Wednesday.
They were awarded a cheque for €5,000 which they donated to help other big families.
Mi agradecimiento a Rosa Pich-Aguilera por dedicarme su libro. En el nos enseña el día a día con sus 18 hijos pic.twitter.com/wL2GygzoBX— Alfonso Alonso (@AlfonsoAlonsoPP) December 9, 2015
Rosa gave Spanish Health Minister, Alfonso Alonso a signed copy of her book.
The family was chosen because they are "an example of struggle and overcoming" said the ELFAC.
José and Rosa's first child was born with a severe heart defect and despite the fact that doctors only gave her three years to live, she died in 2012 aged 22 after completing her Masters.
The couple's next two children died of the same heart condition; one aged only 10 days and one at 18 months.
After the health issues of their first three children, doctors advised José and Rosa not to have any more - but amazingly they went on to have a further 15.
The couple, who are members of Opus Dei, an organisation within the Catholic Church, founded a charity to help children with heart conditions and Rosa has written a book about her experience as a mother of Spain's largest family, "How to be happy with 1,2,3… children".
The family was preselected by a jury along with six other large families around Europe and was finally chosen as “an example of struggle, desire to excel and commitment to life”, said the ELFAC.
The family has appeared on television programmes around the world, from a BBC report "The biggest family in the world" to South Korean news and dozens of Spanish documentary shows.
It seems big families run in the family as José Maria is one of 16 and Rosa had 13 siblings.
Members of Opus Dei are famous for having large families and as a mother who has borne 18 children, Rosa described them as a "gift from God".
"I'm a member of Opus Dei but neither Opus nor the Church has ever told me how many children to have," she said in a 2009 interview with Camino Católico.
"As a Christian, we see children as a gift from God and I will always accept any gift."