Theresa Davis was arrested on suspicion of child endangerment on Thursday after officials at Susan LaVorgna Elementary School in Winchester discovered she was allegedly intoxicated, said the sheriff's department.
Officials were alerted to the potential problem when co-workers found an illegible hall pass Davis allegedly wrote for a student.
Davis was taken out of the classroom, occupied by 23 third-grade students.
She was briefly detained, then turned over to a family member.
The case has been submitted to the Riverside County District Attorney's Office for review
City News Service contributed to this report.