An annual Bank of Scotland survey found 21% of people had not put any money away - up from 18% a year earlier.
The How Scotland Lives study also found 38% of Scots had savings of less than £2,500.
More than one in 10 savers said they were just saving towards a short-term goal, such as a holiday, while the same proportion were saving only for the long-term.
More than a third said they were saving for both.
The research also found that people in Glasgow were putting away the least amount, with 27% saying they did not have any savings to their name.
Bank of Scotland director Mike Moran said: "Our research suggests that many Scots have literally nothing to fall back on if they were to get into financial difficulties.
"It's recommended that everyone has three to six months' wages in savings, just as a back-up in case something unexpected happens."
The bank polled more than 2,000 people across Scotland in December last year.
A growing number of Scots have no savings, according to a new study.