Scotland's high-street stores received a "badly-needed lift" with warm weather last month contributing to a rise in sales.
Total sales for the month were 1.8% higher than a year ago while like-for-like sales, which strip out factors such as new store openings, were up by 0.9%.
Ian Shearer, director of the Scottish Retail Consortium, said the unusually early sunshine had encouraged shoppers to buy summer clothes, outdoor furniture and gardening supplies, while food retailers saw customers buy barbecue meats, salads and ice cream.
But he said some retailers were still facing a "struggle for survival" and added: "It will take more than a few weeks of warmth to bring Scottish retailing back to full health."
Mr Shearer said last month's sales figures were the best results for almost a year.
He also pointed out that sales last March had been "weak" and added that the increase in Scotland was not as strong as the UK as a whole, where total sales were up by 3.6%.
Consumer caution and the weakness in the housing market hit sales of furniture and floor coverings, with sales of big ticket items, for example fitted kitchens and bathrooms, suffering most.
The latest Scottish Retail Consortium-KPMG retail sales monitor showed that total food sales in March were 4.2% higher than last year while like-for-like food sales were up by 2.4%. However, total non-food sales were 0.4% lower than March 2011, with like-for-like sales down 0.5%.
A Scottish Government spokeswoman said: "The increase in retail sales over the last month is welcome and echoes the latest figures available from National Statistics sources which show that the volume of retail activity in Scotland increased by 0.9% during the last quarter of 2011. This matches the growth rate in Great Britain over the same period.
"However, it is clear that circumstances remain difficult due to a lack of growth in the UK economy and we need Westminster to take action to enhance economic security. We are taking every possible step to enhance economic and consumer confidence, as well as support business through difficult trading conditions."