Khan Ahmed Shuvo, the newly-elected Member of Parliament (MP) from the Tangail 7 constituency, took the oath at the Jatiya Sangsad Bhaban on Saturday.
Speaker of the parliament Shirin Sharmin Chaudhury administered the oath to Shuvo, who was elected in the by-polls with the ruling Awami League's ticket.
Parliament Secretariat Additional Secretary Tandra Shikder conducted the swearing-in ceremony, said a press release. Chief Whip Noor-E-Alam Chowdhury was also present.
After taking the oath, Shuvo signed the oath book as part of the traditional ceremony for the lawmakers.
Ahmed Shuvo won the Tangail 7 (Mirzapur) by-polls, defeating Jatiya Party's candidate Jahirul Islam Jahir, on January 16.
The parliamentary seat had fallen vacant after the death of Awami League lawmaker
Ekabbar Hossain on November 16 last year.