Stand Up to Racism Scotland said the counter-protest “reflected the true community of Falkirk” and included trade unions, faith groups, LGBT+ organisations, and refugee rights advocates, “all united in peaceful opposition to racist hate.”
The group accused some demonstrators of launching flares and missiles at the counter protest, and of shouting “vile sexist abuse”.
A spokesperson said: “Saturday’s events are a stark warning: the far-right poses a direct threat to life and safety in Scotland.
“The events in Falkirk show the urgent need for unity to prevent the far-right from spreading hate and putting lives at risk.”
The rallies follow similar protests and counter-protests in Aberdeen earlier this month.
About 40 people protested against asylum seekers outside the former Patio Hotel on 9 August, with about 200 anti-racism protesters attending.
The event had been previously publicised on social media.
There were no reports of arrests amid a heavy police presence.
Another hotel in the Summerhill area of Aberdeen was also subject to a recent protest.