There continues to be a rise in the number of prisoners being committed to custody.
According to the Prison Service's Annual Report for 2011, almost 14,000 people were sent to jail last year - 194 more compared to 2010.
Of those, 86% were male and 14% were female.
The average cost of keeping a person in prison last year was over €65,300, a decrease of over €5,000 compared to the previous year.
The Irish Prison Service says the reason for the decrease is because of reduced expenditure and an increase in the provision of bed capacity.