Children were evacuated from the paediatric ward in North Middlesex University Hospital after a fox fell through the ceiling.
The animal is believed to have climbed into the roof while building work was being carried out at the hospital in Edmonton.
A spokesman for the hospital told ITV London: "Staff evacuated eight children from the ward and the RSCPA then removed the fox."
The spokesman said the fox fell into the "non-patient" area of the paediatric ward after managing to get into the ceiling during major building work.
Following the incident in late June, the ward was shut for three days while work was undertaken to improve the security and prevent anymore animals from gaining access into the hospital.
No patients were disturbed by the incident.