Child Abuse Squad detectives charged a 58-year-old male teacher on Monday following the discovery of a video recording device in a toilet cubicle at a primary school.
The device was located, seized and is the subject of a forensic examination.
Detectives have determined that a number of students were recorded on the device, which was positioned inside a toilet cubicle at the school.
To protect the identity of potential child victims the school cannot be named.
Parents of children identified as having been recorded will be contacted by detectives and provided further information regarding the investigation.
The teacher has been charged with 27 counts of indecently record a child under 13 Years, 15 counts of attempt to indecently record a child under 13 Years and 10 counts of unlawfully install an optical surveillance device.
He is next due to appear in the Perth Magistrates Court Monday, April 11.