The Survation poll for The Sunday Post found 72% are either very or somewhat concerned about how the state pension would be funded in the event of a Yes vote in next month's referendum.
Almost half (48%) said they also had concerns about the funding of their private pensions under independence.
Meanwhile 59% said they did not feel well enough informed about what would happen to their state or private pensions.
Neither Better Together leader Alistair Darling nor First Minister Alex Salmond polled highly when voters were asked which politician they trusted most on pensions, scoring 24% and 12% respectively.
The poll put support for Yes in the age group at 32.6%, with No at 54.8% and 12.6% undecided.
Excluding those who have not made up their minds, backing for independence was at 37.3%, while 62.7% supported the Union.
The poll of 1,003 Scots over the age of 60 was carried out last week.
Scottish Conservative MSP Annabel Goldie said: "No wonder pensioners are worried about independence. We know from the infamous leaked paper prepared by John Swinney that he was worried about pensions under independence.
"Supported by the broad economy of the UK we know that our pensions are safe. With Alex Salmond's independence our pensions are not. He is a man of two certainties. His passion and enthusiasm for what he wants and his complete and utter inability to tell the rest of us what we would get.
"What currency would our pensions be paid in? Alex Salmond simply doesn't know. It is completely unacceptable."
A spokesman for Yes Scotland said: "The state pension is guaranteed to be paid on time and in full in an independent Scotland. The UK Government has told pensioners: 'If Scotland does become independent this will have no effect on your state pension; you will continue to receive it just as you do at present.'
"And spending on benefits and pensions will be more affordable in an independent Scotland than the UK as a whole, because it takes up a smaller proportion of both our tax revenues and national income.
"Scotland's one of the wealthiest countries in the world and with independence we'll have the opportunity to design an economic policy that puts job creation in Scotland first."