World Rugby says it wants to "establish the facts" after fans complained of chaotic scenes outside the Stade de Marseille before England's World Cup match against Argentina.
Delays getting into the stadium meant many fans missed the start of England's 27-10 win.
Former England hooker Brian Moore described the scenes as "beyond shambolic".
World Rugby said it has launched an investigation.
"We are aware of delays experienced by fans entering Stade de Marseille for the Rugby World Cup 2023 Pool D match between England and Argentina this evening," World Rugby said.
"While fans were able to take their seats, fan experience is paramount, and we are working with all stakeholders to establish the facts and implement measures to prevent such delays for the remaining Rugby World Cup 2023 matches at the venue."
Speaking about the scenes at the stadium, England fan Pierre told BBC Radio 5 Live Breakfast: "It wasn't good. The main entrance to the whole stadium is one funnel, where it was just chaos."
France's organisation of major sporting events is under scrutiny, given the scenes before and after the 2022 Champions League final at the Stade de France, which Liverpool lost 1-0 to Real Madrid, and with Paris also hosting the 2024 Olympics.
Liverpool fans were kettled into dangerous crushes before last year's Champions League final and sprayed with tear gas by police as kick-off was delayed by 36 minutes - and fans were also attacked by gangs as they left the match.
Officials initially blamed Liverpool supporters but later apologised as an independent panel found Uefa and the French authorities responsible for the near "mass fatality catastrophe".
Prior to the Rugby World Cup, France's sports minister Amelie Oudea-Castera said the country had "learned lessons" from that episode.
However, some supporters at the ground in Marseille on Saturday claimed on social media that they were concerned for their safety as they queued to get in.
"The organisation at the Marseille stadium was beyond shambolic," Moore wrote on X, formerly known as Twitter.
England fan Pierre added on BBC Radio 5 Live: "It reminded me a little bit of the footage for the Champions League match in Paris that Liverpool were in. We were in the queue for over an hour and couldn't move.
"There were kids, people on crutches. There was no communication whatsoever, couldn't get any signal.
"We were trying to find out online if the match was going to be postponed or not, just couldn't get any news. It was bizarre, really bizarre."