A Brisbane grandmother has been charged with attempted murder after she allegedly slashed her four-month-old grandson’s face multiple times with a knife.

The little boy was found in his cot with facial injuries at a Ridgeway Street home at The Gap on Tuesday morning by his mother.

She had been visiting the home with her son when she was woken by the infant’s crying.

It is understood the 64-year-old grandmother was nearby, and a large knife was also found at the scene.

“The mother found the child in a distressed state with injuries to his face,” Inspector Daniel Bragg told reporters outside the crime scene.

“She’s clearly distraught over what’s occurred. She’s provided police with all the assistance she could.”

Insp Bragg said paramedics who were called to the home, as well as the first police officer on the scene, were visibly upset.

“It was distressing to see such injuries to such a small child,” Insp Bragg said.

“This is the worst-case scenario.

“We deal in trauma, we’re used to trauma. But probably the most affecting job you can go to is one involving a child.

“Clearly when a young child has sustained such critical injuries this isn’t the work of a well-adjusted, happy individual.”

The baby was rushed in a critical condition to the Lady Cilento Children’s Hospital, where he underwent surgery.

His mother was by his side in hospital.

The woman is due to appear in Brisbane Magistrates Court on Wednesday.

-AAP