He secured 47 out of the 59 votes in the House which included 36 votes of the NPF, 4 of the BJP and 7 from the Independents, Speaker Imtiwapang said.
Former chief minister Shurhozelie Liezietsu bagged 11 votes -- 10 of the NPF and one Independent, the Speaker said.
He was not present in the assembly as he is not a member.
Zeliang was sworn-in on Wednesday replacing Shurhozelie Liezietsu, who was sacked by Governor P B Acharya.