Food sales increased in February but overall Scottish sales declined year-on-year by 1.9%.
The Scottish Retail Consortium (SRC) said 2017 had "got off to a somewhat sluggish start" following a second successive month of falling sales.
It suggested consumers were responding to a combination of moderate wage growth and rising overall inflation.
SRC director David Lonsdale said: "In recent months we've seen a polarisation in the performance of food and non-food categories, which continued in February.
"Food sales continued to edge up, helped by good sales of wine and chocolates for St Valentine's Day as well as stronger demand for grocers' meal deals, which perhaps hints at less eating out during the period as consumers reined in spending.
"By contrast, non-food categories fell back once again, particularly clothing, footwear and household appliances, though there was continuing interest in mobile phones, wearable technology and a revival in gaming products."
He added: "These figures suggest Scottish consumers are maybe beginning to tighten their belts and acknowledge the strain from rising overall inflation and moderating wage growth, with council tax set to creep up soon too."
Scottish retail sales fell last month as consumers started to "tighten their belts", according to new figures.