The number of racing fans visiting the Isle of Man for the 2017 TT festival rose by 6% on the previous year, according to government figures.
The TT visitor survey showed that 45,054 people travelled to the island in June, compared with 42,420 in 2016.
The report estimates that the festival brought in about £24.6m to the Manx economy.
The recently-published research also indicated a 40% rise in the number of TT fans aged 18 or under.
Visitor numbers peaked on 4 June when there were about 26,600 tourists on the island, the survey said.
The date - known as Mad Sunday - gives visiting bikers the chance to ride the TT course, part of which is derestricted.
At its peak in 1913, the island's tourism industry attracted more than 660,000 people every year.