Union Street was once Aberdeen's main retail hub, but since 2009 faced competition from the Union Square complex with shops, restaurants and a cinema.
Commercial property expert Richard Noble said from August the street level vacancy rate was down to 18%, back to where it was in February 2020.
This follows a major community effort from the team here at Our Union Street. We host regular clean up events to improve the look of the street with an army of likeminded volunteers who want to see an increase in occupancy on the Granite Mile.
Mr Noble told told BBC Scotland News that the new occupancy figures were a "pleasant surprise".
“Since 2020 we have seen the percentage rise from 18% to 25%, peaking in November 2022," he said of the vacancy rate.
"Since that time the number of empty units has gradually been falling from a high of 48 to 34."
He cited factors including a "gradual improvement in sentiment" since the pandemic, and a more flexible approach from landlords in relation to rent, incentives and lease duration.
Mr Noble described an empty shops grant scheme launched by the city council last year as "crucial" and urged the local authority to consider a similar scheme for the upper floors.
He explained: "Given the success of the empty shops grant scheme, if a similar scheme could be introduced for upper floors that might encourage developers to show a bit more interest in these upper floors, then I think that would be money well spent."