The poll was conducted from 22-27 April among 1,015 people aged 16+ in Scotland.
Overall, the poll shows 63 per cent believe Scotland's interests would be better represented with more SNP MPs, compared to just 16 per cent who think they would be worse represented.
Among No voters, 45 per cent think Scotland's interests would be better represented, compared to 26 per cent who think they would be worse represented.
The 45 per cent figure equates to some 893,000 of those who voted No last September.
SNP General Election campaign director Angus Robertson said:
"Significantly, the polling indicates that nearly 900,000 people who voted No last September share the view that electing more SNP MPs on Thursday will mean that Scotland's interests are better represented at Westminster.
"Our campaign can unite Scotland - and if we unite the country to vote SNP on Thursday, every part of Scotland will benefit."