Ziradei, located in the Siwan district, is one of the 243 state assembly constituencies in Bihar. Current MLA from this constituency is Amarjeet Kushwaha of the Communist Party of India (Marxist-Leninist) (Liberation) (CPIMLL). Kushwaha secured 69,442 votes in the 2020 elections, beating Kamala Singh of Janata Dal (United) (JDU) by a margin of 25,510 votes.

The 2015 election data showed the total number of registered electors were 253,612. As many as 137,613 electors in this constituency during the 2015 elections were male, 115,995 were female and 4 belonged to the third gender. Voter turnout in this election cycle was 53.62% as 135,983 electors out of the total registered electors cast their votes.

In the last legislative assembly elections in 2020, the Election Commission documented the total number of registered electors at 277,386, where 146,349 electors were male, 131,028 were female and 9 were of the third gender in this constituency. Voter turnout in this election cycle was 52.07% as 144,427 electors out of the total registered electors cast their votes.

The 2024 Election Commission data shows the total number of registered electors in the constituency to be 283,758. Male registered electors are 148,271, and female are 135,475. As many as 12 electors of the third gender are also registered. Polling for this constituency took place in the first phase of elections on November 6, 2025.

Ziradei is the birth place of the first president of independent India, Dr Rajendra Prasad. He was an Indian independence activist, lawyer and scholar. Mahatma Gandhi used to consider Ziradei as a pilgrimage site because of its association with Dr Prasad.

This constituency covers an approximate land area of 265.25 square kilometers and its geographic coordinates are 26°13'35.8"N 84°12'43.2"E. Ziradei shares borders with four other legislative assembly constituencies of Bihar, namely Hathua, Siwan, Raghunathpur and Darauli. It also shares an interstate border with Uttar Pradesh.