Some 331 new cases of HIV were diagnosed last year, the lowest level in 10 years, official figures show.
According to the Health Protection Surveillance Centre (HPSC) there continues to be a high level of gay and bisexual men testing positive, with 134 new cases in 2010, the second highest level recorded, but a slight fall on the 138 recorded in 2009.
Tiernan Brady, director of Gay HIV Strategies and member of the HIV Services Network, called for a better understanding of the reasons for the high numbers.
"Prevention of the new HIV infections, along with support for people living with HIV, must remain at the core of Ireland's HIV strategy." he said.
"It is easy to think that HIV/Aids is something that has gone away, something that happens somewhere else to someone else, but as the Irish figures show this is not the case.
"Reduction in HIV infections can only be achieved through government and organisations working in partnership and delivering services based on the best available evidence."
The HPSC said 10 people died of Aids in Ireland in 2010. Its report also showed almost 6,000 people in Ireland live with HIV. Some 240 males and 89 females were diagnosed with HIV last year, a 16.2% decrease on the previous year.
It is the lowest number of new cases since 2001 when 299 cases were identified.
The HIV Services Network, the umbrella group representing NGOs providing services to those affected by HIV and Aids, marked Irish Aids Day by calling for a renewed focus on prevention and highlighted the importance of effectively tackling stigmatisation and discrimination.
Meanwhile, Open Heart House in Dublin and the Sexual Health Centre in Cork have joined forces to launch the Open your Mind awareness campaign to offer advice and support to people living with HIV and depression.