The Educational Institute of Scotland (EIS) union called for ministers to make a firm proposal on the future design of the Scottish Teachers' Superannuation Scheme or face a move towards strike action.
The call comes after drawn-out negotiations between the Government and the EIS on finding a Scottish solution to UK-wide pension changes.
In March, the EIS held back from industrial action to enter into pension scheme discussions with the Scottish Government.
However, after a cancelled meeting this week, Larry Flanagan, general secretary of the EIS, said: "After many months of talks, no offer has yet been made and no response given to our proposals to protect 65 as the normal age for retirement.
"Frankly, the patience of the teaching profession is becoming increasingly thin.
"The message is clear – stop stalling and produce a meaningful offer on pensions, or face a return to industrial action by Scotland's teachers."
Alan McKenzie, acting general secretary of the Scottish Secondary Teachers' Association, added: "We have acted in good faith and expect more than prevarication in return. It is now time for the Scottish Government to put up or shut up."
A Scottish Government spokesman said: "We have engaged early and in good faith with public sector trade unions to agree a way forward on pensions reforms and made good progress through these negotiations."