According to Open Doors, many foreign Christians have left the country and local Christians are facing increasing persecution.
On top of that the country has been dealing with civil war and famine.
Despite these factors, there have been reports of Christianity growing.
Population: 28.1 million (A few thousand Christians)
Main Religion: Islam
Open Doors' World Watch List Rank: 9
The power vacuum created by the civil war has allowed radical Islamist groups to gain significant influence
Christians have been killed and abducted by Islamic radicals, including 16 people killed in an attack on a Christian care home for the elderly
Source: Open Doors
One Muslim convert, Jamil, who is now a pastor, told Open Doors that after foreign Christians were forced to leave at the start of the civil war, the local Christians were unsure how the church would survive.
He said: "Now the foreigners are mostly gone, we actually had to take the lead ourselves. At first it seemed the house church movement would fall apart, but gradually, local Christians started taking responsibility and took up leadership positions. They may not have been highly trained, but they share the knowledge they have and support each other."
Speaking on News Hour, Tania Corbett from Open Doors said it seems to be the country's political difficulties which have caused people to turn to faith.
"This adversity seems to strengthen the churches that are there and people find all sorts of incredible ways to share their faith, inspire others and spread the word to others."
Yemen is a tribal society and leaving Islam is seen as a betrayal of the tribe.
Corbett explained that Yemeni Christians face severe dangers from their own families when proclaiming their beliefs.
"There are sadly incidents where people are not only thrown out of their family for choosing to follow a Christian faith but often will be killed because their family have found out that they are Christians.
Yemen is number nine on Open Doors' World Watch List for Christian persecution.