New figures show nearly seven in ten prisoners currently in custody had previously been committed to an institution.
The Irish Prison system isn't working, according to Aontú.
Figures released to the party show there are 60 more prisoners in custody than there are beds available at institutions around the country.
Its Leader, and Meath West TD Peadar Toibín, says "until we provide supports to citizens with addiction to drugs and citizens with poor mental health services we are just going to keep filling our prisons."
He also says there needs to be "wrap around counselling supports, addiction treatment, rehabilitation plans and also properly funded chaplaincy services."
The Party is also calling for the introduction of more prison beds.
The figures show of the 4,581 prisoners in custody, 3,197 had been previously been committed to an institution.
That equates to just under seven in ten prisoners.
Deputy Toibín says "It is clear our prison system is not working and is literally recycling hundreds of people through the prison system again and again."