Pubs in Scotland are failing to ensure spirit are served in correct measures of 25ml and 35ml.
Between July 31 to August 18 trading standards officers in 25 of Scotland's 32 local authorities visited 193 licensed premises as part of Fair Measure Fortnight.
A total of 343 spirit samples were purchased - out of these only 39 were accurate spirit measures while 155 samples (45 per cent) were short measures. Nearly the same number - 148 samples (43 per cent ) - resulted in a measure that was too big. Some local authorities reported individual deficiencies of 20 per cent or more with one local authority finding short measures were served in over a third of measures tested.
Licensees who fail to serve the correct measures under the Weights and Measures Act 1985 face a fine of up to £5,000.
Ken Daly, chairman of the Society of Chief Officers of Trading Standards in Scotland, said: "This is a very disappointing outcome and the results certainly justify local authorities carrying out this sort of project. The extremes of measures at both end of the spectrum show that we need to work with the licensed trade to train staff to provide accurate measures to consumers."
Colin Wilkinson, secretary of the Scottish Licensed Trade Association (SLTA), said: "The results of this survey emphasise the need for licensees and their staff to receive the proper training in all aspects of managing licensed premises. The SLTA looks forward to working with trading standards to review and update existing training."