Of 200 GPs responding to the poll, 91% said that paperwork had increased since 2006, with GPs now forced to work at evenings and weekends to meet increasing demands.
A total of 23% said it takes up 50-74% of their time and 1% said it takes more than 75% of their time.
The survey found 51% of GPs spend 25-49% of their time on paperwork and just 25% said they spend less than a quarter of their time on it.
GPs said many of the forms they have to complete are irrelevant to patient care. One said: 'I'm spending too much time on paperwork. I'm trained to treat patients, not tick boxes. We are all suffering death by data collection of dubious validity.'
Another said: 'There has been a shift. Previously a lot of paperwork was beneficial but recently it's been more filling in funding approval forms and data captures for health boards.'
Dr John Canning, secretary of Cleveland LMC, said GPs were facing an increasing administrative burden as the volume of PCT circulars, NICE guidance and emails has increased.
'GPs are staying longer at the practice as it's less easy to take the work home because you need to access your NHS email account,' he said.
GPC negotiator Dr Chaand Nagpaul said it was unhealthy for GPs to have a poor work-life balance as a result of having to spend weekends on administrative work. 'There is a need to address the issue of workload and ensure we reduce unnecessary bureaucracy,' he said.
He added that time spent on paperwork was set to increase with the introduction of clinical commissioning.
'Most GPs are spending time on clinical commissioning activities on the basis of goodwill,' he said. 'GPs are finding the workload involved is far greater than the time being provided for in their agreements.'