'We have had the support of around 85 percent of doctors,' Vaclav Smatlak, the president of the Union of General Practitioners (SPL), the biggest doctors' association, told AFP.
However, emergency treatment was provided despite the protest.
Doctors say the current minimum rate of 36 koruna a month (around 1.3 euros/1.8 dollars) paid by health insurers for every patient on their books is insufficient.
They warn that the current situation could lead to a shortage of medics soon.
VZP, the country's biggest health insurer, Wednesday tabled a fresh offer of 42 koruna per patient which doctors were due to discuss later in the day.
'I cannot say at the moment what the outcome will be,' Smatlak said.
Doctors have threatened to step up their action with strikes spread over several days if their demands are not met.
The Czech Republic has around 5,000 general practitioners, of whom 80 percent are represented by the SPL, as well as some 2,500 paediatricians.