Hoteliers have called on the Minster for Justice, Equality and Law Reform, Mr McDowell, to introduce a certificate system to allow children to remain in hotel bars after 9 p.m.
They want the system introduced before the height of this year's tourism season.
Provisions in the Intoxicating Liquor Act 2003, introduced last August, prohibit those under 18 from bar areas.
At the annual conference of the Irish Hotels Federation in Killarney yesterday, outgoing president Mr Jim Murphy said this was causing "unnecessary difficulties" to hoteliers and the 2.6 million visitors on family holidays.
He said there was "substantial feedback" of dissatisfaction from IHF members and this was before a full tourist season under the ban, he said.
Mr Murphy said parents did not feel comfortable leaving their children in bedroom areas unsupervised, while they enjoyed a meal or entertainment elsewhere in the hotel and this was "wholly understandable".
There were also worries that the restriction was damaging Ireland's image as a relaxed family-friendly environment.
"A relaxed pace of life with little bureaucracy is what attracts visitors to Ireland - these restrictions portray somewhat the opposite view," Mr Murphy said.
A children's certificate system along the lines of that in place in the UK would allow local gardaí to grant suitable hotels permission to have children with their parents in the bar area of hotels after 9 p.m. when food was being served or where there was family entertainment.
Gardaí could withdraw certificates where there was concern.
He called on Mr McDowell to provide for the certificate in the codified liquor legislation which he plans to introduce this year.
Mr Murphy also said a mandatory ID card system should be put in place to facilitate age identification. This would eliminate the perennial problem of assessing people's ages.
The IHF supported Mr McDowell's efforts to tackle underage drinking but current individual checks were impractical and unreasonable, and they interfered with family enjoyment of sporting and social occasions, he claimed.
Irish visitors had buoyed up a flat year for Irish tourism in 2003, and were to be commended for their support of the industry, Mr John Power, chief executive of the IHF, said.
They took over 3 million holidays and short breaks last year and the €1.1 billion they spent brought total revenue from tourism up to €5.2 billion in 2003.
Some 75 per cent of hotel rooms outside of Dublin were taken up by Irish people and the figure nationally was 57 per cent for short breaks.
Mr Power blamed the war in Iraq for the "flat year in terms of visitor numbers".
The preliminary figures of 6.1 million overseas visitors in 2003, representing a 4 per cent increase in visitor numbers on 2002, had to be viewed in the context of the decreases of the previous two years, he said.
A more substantial increase had been hoped for.
The IHF urged its members to co-operate on the smoking ban.