The man, Md Al Amin, 26, a resident of Islambagh, was admitted to Dhaka Medical College Hospital after the incident on Wednesday evening.
Shahbagh Police Station Inspector Zafar Ali Biswas said the woman was taken to the police station.
Zafar said the two has been in a relationship, but their families asked them to break up.
Amin tried to harass her at Fuller Road when she was on her way to an uncle’s house in the evening, the inspector said.
“As he tried to snatch away her mobile phone, the woman stabbed Al Amin twice from the back,” he added.
