The attorneys said in a joint statement they had decided to withdraw on Tuesday “to preserve the dignity of the task of defence.”
Their decision followed a technical court ruling which they interpreted as tantamount to a “refusal to call witnesses”.
They were defending Muhammad Kattani and Muhammad Abd al-Uhab Rafiqi, charged with criminal association, undermining the internal security of the state, acts of sabotage and assassination after the five May suicide blasts that left 45 people dead.
The court appointed a new lawyer to take over the defence.
The two defendants are said to be the “theorists” of Salafia Jihadia, a movement accused of involvement in the bombings and were arrested with around 600 others in massive police sweeps following the attacks.
Last month the Casablanca court sentenced four Islamist activists to death and dozens to heavy jail terms for the bomb attacks.
Twelve of the 45 killed in the attack targeting a Spanish restaurant, the Belgian consulate, a Jewish community centre, a cemetery and a hotel, were believed to be the assailants.
Moroccan investigators said the attacks were organised by Salafia Jihadia, which mainly recruits among residents of poor suburbs in cities including Casablanca.