Both Dev and Oza are Congress spokespersons currently. Oza was appointed the Mahila Congress chief in August 2013.
"Congress president Sonia Gandhi has approved the name of Sushmita Dev, MP, as the president of All India Mahila Congress with immediate effect in place of Shobha Oza. The party appreciates the work and contribution of the outgoing president," a statement from AICC general secretary Janardan Dwivedi said.
Dev, the daughter of former Union minister Santosh Mohan Dev, who died recently, hails from Assam and represents the Silchar Lok Sabha constituency.
The change is the part of party's efforts to rejuvenate its women's wing.