The number of offences of indecency - anything ranging from rapes to kerb-crawling - dropped just under 5.9 per cent in April-June 2014 compared with the same period a year before.
Preliminary as yet unofficial figures from Police Scotland showed there were 2,187 such crimes recorded, although there was no breakdown of the most serious ones, such as rape.
Figures were up in Edinburgh and Aberdeen but a large drop in Glasgow, from 441 to 341 in the quarter helped push the overall figures down.
Officials from the Scottish Police Authority, which published the figures, urged caution in interpretation of numbers for individual council areas.
The report said: "Seventeen authorities showed decreases in numbers of recorded sexual crimes, the most noteworthy are the larger authorities of Glasgow and Fife.
"The decrease in Glasgow was primarily due to a decrease in rape and sexual assault and prostitution-related crimes."
Sex crime in the quarter, however, remains far higher across Scotland than just a few years ago.
The figure, now 2,187, is up from 1,868 in April-June 2011-12.
The number of serious violent crimes - so-called group 1 offences such as murder, serious assault and robbery - has been falling dramatically in recent years.
Group 1 crimes were down again in the quarter, also by 6.5 per cent, while overall crime was down 6 per cent.