Gary Creevey, 65, with an address at Carrigmore Crescent, City West, Saggart, Co Dublin, pleaded guilty to one count of indecently assaulting a boy in the North Monastery Primary School in Cork city on a date between September 1971 and 1 July, 1972.
The court was told that the defendant had pleaded guilty in 2004 to a charge of indecent assault on another boy in the school in 1971.
At that time, he received a six-month suspended sentence after Judge Con O'Leary accepted his previous good record, his efforts at rehabilitation and his response to the complaint.
At Cork District Court today, defence solicitor Frank Buttimer argued that both offences took place at the same time in 1971, but while Creevey was tried for one in 2004, the second offence only came to light nine years later.
Mr Buttimer said he believed that if both were heard in 2004, the court may still have been influenced by the positive attitude of the accused.
Judge O'Leary said he accepted the genuineness of Creevey's remorse.
However, there were two offences, which happened to two very vulnerable people.
He said this caused him sufficient concern to impose a 12-month imprisonment, suspending nine months if he entered into a bond of €500 and keeps the peace for two years.