The incident took place when Ritu Saini (17), a student of eleventh class, was going to the play ground for her daily practice at around 5 pm.
Two boys, in their early twenties, who were waiting for her, took out the acid and threw it on the girl, said Rammehar Saini, uncle of the victim.
He said Ritu was a player of volleyball and had participated in school-level national games held last year.
The victim suffered burn injuries on her face, arms and some other part of the body, said a doctor attending on the girl at the emergency ward of the PGIMS.
The bikers managed to escape from the spot after hurling the acid.
This is the second incident of throwing acid on a girl in Rohtak in a year.
Earlier, two bikers had thrown acid on three girl students when they were returning home after their tuition classes on June 18, 2011.
