The number of children currently smoking has dropped by 17% in 20 years, new research has found.
The Health Behaviour in School-aged Children Trends Report 1998-2018 (HBSC) found that 5.3% of children were smoking in 2018, compared to 22.6% in 1998.
The report also found that fewer children had reported being drunk since 1998.
Research found that 19% of children in 2018 said they had been drunk, compared to 33% in 1998.
The report was led by senior researcher Aoife Gavin in collaboration with the HBSC research team at the Health Promotion Research Centre in NUI Galway.
Compared to the findings from 1998, the study found fewer children using substances, more than half of children exercising regularly, more children feeling pressured by school work and more children feeling low.
The HBSC is a cross-sectional study conducted in collaboration with the World Health Organisation Regional Office for Europe. It runs every four years.
In 2018, 45 countries and regions participated, collecting data on health behaviours, health outcomes and the social contexts of children's lives.
The study compared findings of health behaviour in school-aged children from 1998 to 2018.
The report found there was an overall decrease across all substance use measures.
Among the findings was that fewer children reported cannabis use, with 8.5% in 2018, compared to 12.3% in 1998.
There was also an overall improvement in positive health behaviours.
These included more children brushing their teeth more than once a day (70.1% in 2018, compared to 57.6% in 1998).
More children are now wearing a seat belt on car journeys, with 81.4% in 2018, compared to 41% in 1998.
The proportion of young people doing vigorous exercise four or more times a week has remained stable at 52.1% in 2018, compared to 52.6% in 1998.
Junior Health Minister Frank Feighan said: "This international project has provided us with essential data which has helped to shape and inform policy relating to the health and wellbeing of our children and young people.
"The information contained in this study will be of great importance in terms of future planning and policy direction regarding children's health."
Children's Minister Roderic O'Gorman said: "Ireland is headed in the right direction when it comes to the health of young people, and it is clear that past government initiatives to support healthy choices are having a positive impact on reducing alcohol consumption and smoking, helping to keep our young people safe.
"In February my department launched the Supporting Children Campaign which aims to outline the supports available for children and families during the pandemic. We have also increased funding for youth services in 2021, in recognition of the positive impact youth work can have on young people's lives."
Co-principal investigator Dr Colette Kelly, from the Health Promotion Research Centre at NUI Galway, said: "There is a continuing positive trend in children communicating with parents and reports of good places in the local area to spend free time.
"The report also highlights areas in need of improvement. In particular, more young people are reporting that they feel pressured by school work and there is an increase in the proportion of children who report feeling low.
"The report provides a breakdown of age, gender and social class patterns which provide more in-depth information on each of the indicators."