The result is expected to be declared by late afternoon, a Government official said.
Thirteen candidates, including nine Independents, were in the fray. The by-election was necessitated after Congress MLA from the constituency Ramreddy Venkat Reddy passed away in March.
The contest is expected to be a triangular one between ruling Telangana Rashtra Samithi (TRS), Congress and the CPI (M).
TRS has fielded State Roads and Buildings Minister Tummala Nageswara Rao while opposition Congress has named Venkat Reddy's wife, Sucharita Reddy as its candidate.
The ruling TRS has tried to woo voters on the "developmental work" it plans to undertake in the constituency if elected, while Congress has tried to "encash" the sympathy wave due to Reddy's sudden demise.
CPI (M) has fielded P Sudarshan Rao for the seat.