Police made 133 arrests and recovered 16 knives at the Notting Hill Carnival on Sunday, Scotland Yard said.
Officers detained 42 people on drugs offences, 20 on suspicion of possession of an offensive weapon and seven on public order offences.
A further two people were arrested on suspicion of sexual offences, three for common assault and 12 on suspicion of possessing psychoactive drugs.
Police were operating with enhanced stop and search powers in a bid to crack down on violence.
Stop and search
Scotland Yard said it would also be imposing a Section 60 order (meaning police can stop and search attendees) across the carnival's geographical area between 9am and 11.59pm on Monday.
The order allows officers to search people if they believe they may be carrying offensive weapons or in anticipation of violence.
Notting Hill Carnival Gold Commander Dave Musker said: "On Sunday, my officers along with colleagues from the British Transport Police arrested 133 individuals for a range of offences and 20 weapons were seized, including knives.
"I am confident that the Section 60 order imposed yesterday prevented these dangerous items being brought to Carnival, and based on the intelligence at my disposal, I consider it proportionate and necessary to ensure a safe Carnival today."
The Bank Holiday weekend event is being policed by the highest number of officers in six years.
Almost 7,000 officers, some from the Metropolitan Police's newly formed Violent Crime Task Force, will be policing Monday's event to "combat the threat of violent crime".
This is up from the 6,100 on-duty officers at the less busy family day on Sunday.
Undercover police as well as officers from the force's firearms and dog units will be in place.
The event is expected to attract more than a million revellers to its floats, food stalls and music over the course of the two days.