The Fresno Police Department says it happened around 6 pm at an apartment complex near Dakota and Abby.
Authorities said there had been a neighbor disturbance throughout the day and it eventually turned violent, with a 27-year-old woman stabbing a 17-year-old boy.
Investigators say that the boy was trying to break up a fight when the stabbing occurred.
The boy is a relative of one of the residents and was found inside one of the apartments with stab wounds to the chest area.
Authorities arrested the 27-year-old woman, who has been identified as Touluvya Laster.
The boy was taken to CRMC and is expected to survive.