The Royal Society of Edinburgh inquiry has found that deprivation has a far more significant effect on broadband uptake than geography or connection speeds, and that poorer people face exclusion from the growing "digital society".
The body found that current use and uptake of digital technologies differs significantly according to socio-economic, demographic and geographical factors.
It also found that people from the nation's most marginalised communities — the poor, the old and the isolated — are being denied the opportunities offered by broadband.
Inquiry chairman, Professor Michael Fourman, said, "The analysis we present in the report, backed up by the first-hand evidence we heard across Scotland, shows that the digital divide is wider than we thought."
"Figures on broadband uptake at Scottish, or even council level, mask significant variations between postcodes.
"In some areas, nine out of ten households are online; but there are twice as many where most households are still offline.
Some of these are in very remote, isolated communities, but most are in urban areas already facing deprivation.
"The gap between these extremes exacerbates existing social divides, and must be seen as a priority for action."
The society's report, Spreading the Benefits of Digital Participation, will be launched in Edinburgh today.
The government has pledged to make Scotland a world-class fully digital nation by 2020 with 98% of people able to access the internet freely.