General Teaching Council (GTC) for Scotland chief executive Anthony Finn issued the warning in his new year message. GTC Scotland is a regulatory body which aims to maintain and enhance teaching standards in Scotland.
But Mr Finn said that, while education bodies should aim to spend their cash as effectively as possible, budget cuts would have an impact.
He said: "There are those who argue we should aim to achieve 'more with less'. I have heard this mantra frequently in recent months but I am not convinced.
"Yes, we should aim to achieve as much as we can, aiming to spend limited resources as effectively as possible, but we also need to recognise that budget reductions will inevitably mean that some current expectations may no longer be practicable."
The GTC Scotland chief executive said every year brought "challenges and opportunities" but argued "2011 already seems likely to pose some significant challenges for teachers and the wider education community".
Mr Finn conceded "most of the difficult budget decisions" to be taken by councils and others in the coming months would be "agreed in forums outwith our organisational remit".
The results of a review of teacher education by former HM Inspectorate for Education senior chief inspector Graham Donaldson are due next month.