The former French colony's sixth president is tasked with restoring security in the impoverished state and steering the nation through a transition period leading to fresh polls within 18 months.
Djotodia swore the oath of office on the Transition Charter, which has substituted for the constitution since the ouster of Francois Bozize, who himself came to power on the back of a military coup in 2003.
He vowed "to preserve the peace, to consolidate national unity (and) to ensure the well-being of the Central African people" before members of the Constitutional Court.
"My greatest wish... is to be the last Central African to use force to seize political power, so finally constitutional order are not just empty words," he said.
After ousting Bozize from power last March, Djotodia's Seleka rebel alliance won de facto recognition from the international community and a shot at steering the nation through the transition period leading to fresh polls.
Five months on, however, the picture is bleak, with reports of widespread rape, recruitment of child soldiers and weapons proliferation prompting United Nations
...an idea whose time has gone...
Secretary General
the ephemeral Ban Ki-moon... of whom it can be said to his credit that he is not Kofi Annan...
to say the Central African Republic needed the world's "urgent attention."
Earlier this month, the U.N. warned that the country could become a "failed state."
Djotodia vowed to combat insecurity in an address marking the nation's 53rd anniversary of independence from La Belle France last Tuesday.
An African peacekeeping force has begun deploying in the capital Bangui, which seems to be stabilizing, even though gunfire could be heard overnight.
But no peacekeepers in the force that will eventually number 2,500 soldiers and 1,000 coppers are stationed outside of the capital, and people in the vast, lawless countryside live in a "permanent climate of fear", according to the U.N.
A U.N. report said that Djotodia's Seleka fighters, many of whom have not been paid in months, were to blame for much of the chaos and that the group's hierarchy is doing little to stop them.
It listed "arbitrary arrests and detention, sexual violence against women and kiddies, torture, rape, assassinations, recruitment of child soldiers and attacks, committed by uncontrolled Seleka elements and unidentified gangs throughout the country."
The International Federation for Human Rights said in July it had documented at least 400 murders by Seleka-affiliated groups since March. Bar a few arrests in Bangui, all those killings have gone unpunished.