Two motorcycle-borne men threw acid at a 24-year-old girl at Hazratganj in Lucknow, police said on Wednesday.
The incident occurred late Tuesday night when the student of the National Institute of Fashion Technology in New Delhi was returning home, the police said.
The victim's boyfriend Ankur, against whom her parents have filed a complaint, has been arrested.
The girl, who suffered 50 percent burns, is out of danger, the police said.
The motive behind the crime is being investigated.