JN Ganesh was at large after the alleged assault on Anand Singh.
Congress MLA JN Ganesh was arrested on Wednesday near a restaurant at Somnath in Gujarat, weeks after he was declared absconding for allegedly assaulting another lawmaker from his party during a brawl at a resort.
Mr Ganesh was at large after the alleged assault on Anand Singh, both from Ballari district, on January 20 at the Eagleton Resort on the city outskirts, where the Congress had sequestered its MLAs to prevent a poaching bid by the Bharatiya Janata Party (BJP).
The MLA was arrested in the afternoon when he was going to have lunch near Somnath Temple, Ramanagara district superintendent of police Ramesh Bhanot said.
"We had sent a team to Gujarat three days ago following information that he was staying in a hotel there. Today our team got inputs that he was near Somnath temple to have meals at a hotel. He had stopped his vehicle there when we arrested him," Mr Bhanot told reporters.
He said police teams were sent to Andhra Pradesh, Tamil Nadu, Maharashtra and Delhi.
There were three people with him -- two of them from Karnataka and one of his friends was from Gujarat, he added.
Karnataka Home minister MB Patil said the MLA was arrested at 2 pm.
"He will be brought here by a flight in the night," Mr Patil told reporters.
JN Ganesh had allegedly attacked Anand Singh with his fists and a flowerpot, hit him near his eye and kicked him on his chest, according to the complaint filed with the police.
In his complaint, Mr Singh said Mr Ganesh was upset as he suspected that he wanted to finish him off politically and did not support him financially during the Karnataka Assembly polls last year.
A seriously injured Mr Singh was admitted to a private hospital in the city.
Based on his complaint, the police had registered a case of attempt to murder against Mr Ganesh.
Fearing arrest, the Congress MLA did not appear for the crucial budget session of the state legislature, despite a whip.