Most of the GP practices in Kingston have said they will not go on strike on Thursday, according to NHS South West London.
But patients still face cancelled or rearranged appointments.
Doctors will take industrial action this week for the first time in almost 40 years.
The British Medical Association (BMA) has accused the Government of unjustified increases to pensions contributions.
It asked doctors to go to work but only see emergency or urgent appointments.
Health Secretary Andrew Lansley has said up to 30,000 operations could be cancelled, 58,000 diagnostic tests postponed and 200,000 outpatient appointments rescheduled nationally.
He has also said up to 1.25 million GP appointments would be rearranged into the days and weeks following the action.
A spokeswoman for NHS South West London said it had warned GPs planning to go on strike about their contractual obligations to the NHS and their patients.
She said: "Our indications at the moment advise that out of 28 practices in Kingston, 22 will not be taking action.
"However we must stress that all practices should continue to fulfil their contractual obligations.
"Patients should continue to approach their practices in the normal way.
"Those practices intending to take part in the industrial action should be displaying BMA material to advise their patients of this."
Kingston Hospital said emergencies would not be affected by the strike although some routine appointments would be re-arranged.
In a statement on its website the hospital said: “We are working with the doctors to understand how and if this strike action will affect us at Kingston Hospital, but the expectation is that the majority of appointments will go ahead as usual."
Anyone who has not been contacted by the hospital about their appointment should assume it is going ahead, the trust said.
Colin Dance, chairman of the Orchard Practice Patient Participation Group, said: “I work in the NHS and most doctors are saying they are not on strike and they are available for emergencies only but they are cancelling outpatient clinics.
"It is causing quite a lot of disruption."
But he said he had not yet spoken to his GP practice about whether or not it was on strike.
In a briefing paper the BMA said: "Although there will inevitably be inconvenience for some patients, anyone requiring care or investigation that day will get it.
Is your surgery cancelling appointments or going on strike? Call the newsdesk on 0208 744 4244 or email firstname.lastname@example.org