According to the Irish Pharmaceutical Chemical Manufacturing Federation, employment in the sector will rise by 1,000 by 2005.
The first 100 jobs will come on stream within the next year with the remainder in the next three years.
Six major pharmaceuticals companies, including Pfizer Ireland and Glaxxo Smithkline Beecham are investing over €1.2bn in expanding their operations.
With 16 of the world's top pharmaceutical companies operating in Ireland, it is now the second most valuable sector to the economy.
Today's news means that employment in the sector will rise to 25,000 by 2005.