A student attacked a female Devine Middle School teacher in the band hall at around noon Friday.
According to Devine ISD Superintendent Linda McAnelly, the injured teacher was transported to a San Antonio hospital in stable condition.
McAnelly said the teacher was able to call for help.
"(She) had the presence of mind to call the principal and call the nurse and able to apply compress to the injury," McAnelly said.
McAnelly wouldn't release details on how the attacked happened, although a viewer called KSAT 12 News to say the student stabbed the teacher. The student was in police custody.
There was no immediate word on a motive for the attack, which McAnelly called "surprising."
McAnelly said the district alerted parents about the incident via the district's messenger phone system and email. Counselors are also being made available to students.