The animal welfare charity was called in to help after the occupant of the house in Brighton, East Sussex, was taken into hospital in December last year.
RSPCA inspector Liz Wheeler said: "We were expecting to find around 200 budgies but ended up removing 359.
"They were flying free around the semi-detached home so we had to use capture nets to safely catch them and remove them.
"When you entered the property there was a sea of yellow, green, blue and white, with birds perched everywhere. The noise from their tweeting and chirping was deafening."
A charity spokeswoman said the birds were signed over to the RSPCA by their owner who was not able to cope with them but they now faced the challenge of finding new homes for the birds.
Ms Wheeler said: "The budgies have been taken in by a number of our branches, centres and by private boarding establishments across the country.
"The other birds remain in private boarding until we can find space for them at our rehoming centres across the country.
"We'd like the budgies to go to new aviary homes where they can live with other budgies and have lots of space to fly and explore."
The charity's senior press officer Amy De-Keyzer tweeted a picture of the birds saying: "Does anyone want a budgie? @RSPCA_official has 359 looking for homes!!!"
Anyone who is interested in offering one of these birds a new home should visit the RSPCA's website: www.rspca.org.uk/findapet