The Irish Family Planning Association (IFPA) has called for a national survey of sexual behaviour and attitudes among young people.
The call comes after the publication of an Irish Times/tns mrbipoll that reveals one on four 15- to 17-year-olds have had sex.
Ms Catherine Heaney, chief executive of the family planning charity, said quality data was important in informing programmes and policy to respond to sexual activity among young people.
"Polls and surveys, such as this one carried out by The Irish Times/tns mrbi,are useful in building a picture. However, at this stage, in-depth national profiling of young people's experiences and attitudes is necessary to provide us with a comprehensive overall picture."
Ms Heaney said the poll was in keeping with the findings of three other polls which have been undertaken in separate health board areas over the past 12 months.
"Some preliminary work is now under way by statutory agencies to prepare the way for a national survey on sexual attitudes and behaviour.
"It is crucial that the main focus of such a survey will be young people, including those under the age of 17. If this age group is ignored, that survey will have little value," Ms Heaney added.
She said up to now there has been a reluctance at a national level to engage in work to ascertain the experiences and attitudes of teenagers when it comes to sex.
"This was reinforced by a Government decision to deletequestions on sexual activity and contraception, which were contained in a questionnaire from the World Health Organization just last year. This survey was being conducted in schools."
The Irish Times/tns mrbipoll found that of the 15- to 17-year-olds who have had sex, 30 per cent have had one partner and a further 19 per cent have had two.
Just over 4 per cent of the 15 to 17 age group has had sex with more than four people. Some 89 per cent of those who have had sex in the 15 to 24 age group report they normally use contraceptives.