The organisers of Brighton Pride have said "tough decisions" will have to be made ahead of next year's event.
A meeting held after this summer's Pride, attended by officials and the emergency services, concluded it could not continue in its present format.
Overcrowding and the amount of rubbish and broken glass left in Preston Park were said to have been a key issue.
Sussex Police said if the situation was allowed to continue, it could lead to the withdrawal of the event's licence.
In a statement, Brighton and Hove City Council said Pride needed "tidying up".
Pride trustee Geoffrey Bowden said he did not believe the event was under threat.
He said a new board of trustees would shortly be in place and they would have "some pretty tough decisions to make".
"One of them may well be to look at charging, and indeed to do that you're going to have to look at the option of fencing Preston Park, if that is where the event is to remain."
This summer's Brighton Pride celebration, which began in the city as a gay protest in the early 1970s, was the biggest in its 18-year history, with more than 160,000 people taking part in the free event.