The suspects have been referred to the Gulf nation's State Security Court, prosecutor Ahmed al-Dhanhani said.
He accused the group of having "established and managed a branch for ... The international organisation of Egypt's Muslim Brotherhood, without a permit".
The founders of the branch set up an administrative structure aimed at recruiting members for the Muslim Brotherhood, strengthening its presence in the UAE and maintaining allegiance to the main party, he said.
Around a dozen Egyptians, some of them doctors, engineers and university professors, belonging to the group had been arrested between November 2012 and January 2013, according to Human Rights Watch.
More From This Section
The detained group was also linked to a separate network of around 94 Emirati Islamists, including 13 women, who are on trial for forming a "secret organisation plotting to overthrow the regime".
Most or all of the 94 defendants are members of Al-Islah association, which UAE authorities say is linked to the Muslim Brotherhood.
The case of the arrested Egyptians has sparked a sharp deterioration in relations between Abu Dhabi and Cairo, already strained since the June 2012 election of Mohamed Morsi, who hails from the Brotherhood, as Egypt's president.
The Gulf country, which bans political parties, rejected an earlier request from Egypt for the release of its nationals.