A confrontation between two brothers at a home in the 100 block of Dafoste Avenue led to the older brother stabbing his younger sibling, San Antonio Police said.
Officers were called to the East Side home early Tuesday morning around midnight.
Investigators said the 24-year-old younger brother was choking his older brother when the man pulled out a pocket knife and stabbed the younger sibling in the chest, police said.
The stabbing victim was taken to University Hospital. Police did not release his condition.
The older brother was arrested at the scene and will be charged with aggravated assault with a deadly weapon, San Antonio police. Police did not say what led to the fight.