Scotland has been pressing ahead with a full spread of major investment projects despite a £1bn drop in forecast capital spending from £3.3bn to £2.1bn by 2014-15.
Public spending watchdog Audit Scotland said the existing 10-year plan, published three years ago, now needed to be updated in the light of the recession.
Auditors said there was no comprehensive list of major capital projects in progress but estimated about 182 were planned or under way.
The report added: “Although the plan is not quite three years old, the recent economic recession and subsequent reduction of public sector spending, particularly capital budgets, mean that it needs to be reviewed and updated.”
Scottish government spokesman Robert Black, the auditor general for Scotland, said: “With Scotland’s capital budget dropping by a third in coming years, there are difficult choices ahead.
“It now needs to set out a clear view for investment in future years, backed with good information about long-term needs, affordability and constraints.
“This would strengthen debate about spending decisions, priorities and planning.”
A Scottish government spokesman said: “We are deploying £2.5bn of new investment through the Non Profit Distributing model to mitigate the cuts in Scotland’s capital budgets from the UK government.
“This programme is being led by the Scottish Futures Trust, which is working to secure maximum value for money from our infrastructure investment across Scotland.”