A network of organisations is being set up to support homeless people amid rising numbers in the area.
Figures from homeless charity the Four Streets Project fed a total of 666 people in August, more than three times the amount fed in March.
The month-on-month rise has been described as 'very significant' by the charity's founder Donna Ockenden.
She said: "We are so concerned about the continued increase of the numbers of homeless and vulnerable people in Chichester. Going forward we will be sharing these figures with Chichester District Council and Chichester City Council.
"It's not about an influx — a lot of those people have been known to the project for a very long time and some of them are returning having been previously housed."
The numbers only account for the homeless people being fed in Chichester city centre's main four streets. The highest number fed in one night in August was 37.
Donna also announced that the charity would be working with Grandad's Front Room CIC in Bognor Regis and with Canon Mark Payne at St Pancras Church.
"St Pancras has been doing a lot of good work for many, many years and we are intending to work in active partnership with them. We are also having active conversations with Danny Dawes at Grandad's Front Room.
"Again we see and we hear that they are providing much needed front line homeless support in Bognor Regis and Grandad's Front Room and the Four Streets Project are keen to learn from each other, share ideas and ultimately support vulnerable homeless people on our streets."
A network of smaller organisations are in discussions over an approach to tackling the problem.
Danny Dawes, who runs Grandad's Front Room CIC in Bognor Regis said he was looking forward to what he called a 'collaboration'.
"We have always been talking to each other and sharing numbers, challenges and best practise. If anything we are strengthening our relationship," he said.
Part of the discussions are St Pancras Church, The Salvation Army, and Radio Respect CIC.
Danny added: "There are all these little places across Chichester and Bognor that tend to overlap and what we need to do if to get everyone to align with each other.
"We are joining to make ourselves stronger."