The woman had gone to the parlour for her bridal make up shortly before her marriage when the young man barged in and threw acid on her and fled the spot, police said.
The victim, resident of Barnala town, sustained 45 per cent burns and was admitted to the ICU (burn) of a local hospital, where her condition was stated to be stable.
Stating that the girl's face, eyes, chest and abdomen were affected, Medical Superintendent of the hospital Ashwani Chaudhary said it was premature to say whether "she will retain her vision or not".
Two girls, who were doing the bridal makeup for the victim, also came under the attack, but did not sustain any injury, police said. They were examined in the hospital and discharged shortly afterwards.
According to witnesses, the man escaped in a car kept in running condition outside the parlour in Sarabha Nagar, Commissioner of Police (CP), Ludhiana N S Dhillon said.
The marriage of the woman, which was to be solemnized at a resort on Pakhowal road, has been postponed in view of the incident, her family said.
According to preliminary interrogations of the family, the man, also of Barnala, and a friend of the victim's brother, used to make threatening calls to the woman asking her to marry him or face consequences, the CP said.
Police parties have been sent to Barnala to nab the man, he said, adding that the assistance of the local police there has been sought.
Later, Deputy Commissioner of Police (DCP), Ludhiana Harsh Bansal told reporters that a youth has been detained for interrogation in connection with the incident.
Bansal declined to reveal the identity of the detained youth saying efforts were on to nab the accused.