Official figures show the number of female prisoners has doubled in the past six years.
The 2011 Prison Service annual report also showed that while the number of men being committed to prisons stabilised last year, the number of women imprisoned jumped by 12% to 1,902 — 200 more than 2010.
Women accounted for 16% of all people in jail last year, compared to 12% in 2010 and 10% in 2006, when there were just 960 female committals.
The Irish Penal Reform Trust described the development as “worrying” and said there was a need for alternatives for low-level female offenders.
Overcrowding is affecting the whole system, with 15% of the prison population on temporary release. The figures show 785 inmates were given temporary release in 2011 compared to 732 in 2010 (also 15% of the total). The number jumped in recent years compared to 2007, when just 153 people were released early (4% of the population).
Again the problem is most acute in certain prisons, with the two female institutions grossly overcrowded.
Of the 258 females in Dóchas and Limerick on an average day in 2011, 98 were on temporary release (38%). In Limerick, it was almost half.
Cork (male) Prison has seen about one-third of all inmates on temporary release.
The Prison Service report also records a rise in committals for non-payment of fines, as revealed in the Irish Examiner last month.
There were 7,514 committals in 2011, compared to 6,683 in 2010. About 4,470 committals have taken place in the first half of 2012. The rise may be a factor in a 10% jump in sentences of fewer than three months.
Laws enacted last October oblige judges to consider community service instead of short prison sentences.
The report shows there was a 22% rise in the number of people given sentences of between one and five years, but a 16% drop in sentences between five years and life.