The Christians on trial include Pastor Abdolreza Ali-Haghnejad and his wife Anahita Khademi, Mahmoud Khosh-Hal and his wife Hava Saadetmend, Fatemah Modir-Nouri, Mehrdad Habibzade, Milad Radef and Behzad Taalipas, and Amir Goldoust, his sister Mina Goldoust, and his grandmother Zainab Bahremend.
The organisation says the charges relate to their involvement in a house church, and to taking communion wine.
Six other members of the Church of Iran were due to stand trial this month for blasphemy but the trial was postponed twice, the first time to allow prosecutor more time to gather evidence, and on the second occasion to allow the prosecutors to seek the assistance of Iran's traditional churches in determining their guilt.
The six Christians have already served eight months of a one year sentenced for "crimes against the Islamic Order" handed down at a previous trial and are currently out on bail. Their legal team is optimistic that they will their appeal against all charges.
The trials follow a wave of arrests in past months. Between last June and February this year, 254 Christians have been arrested in 33 cities, but CSW fears that the actual number of arrests is much higher.
Rhetoric from some quarters has also turned against evangelical Christians.
In January, the governor of Tehran, Morteza Tamadon, called the evangelical movement “a false, deviant and corrupt sect…placing themselves within the religion of Islam like a parasite and under the cover of Christianity”.
CSW’s National Director Stuart Windsor said, “The harassment and targeting of religious minorities is incompatible with Iran’s responsibilities under the International Covenant on Civil and Political Rights, whereby countries pledge to respect the right of citizens to manifest their religion or belief in worship, observance, practice and teaching.
"The charges against the eleven Church of Iran members constitute a severe infringement on Christian tradition, as they effectively criminalise the taking of Communion, which is a biblical injunction.
"CSW urges the international community to encourage Iran to meet its obligations on religious freedom under the Covenant by ensuring that all members of the Church of Iran, including Pastor Yousef Nadarkhani, who still faces a death sentence for apostasy, receive due process, and are acquitted of all charges that have no legal bearing.”