The figures were released to the Conservatives after Freedom of Information requests were submitted to all eight of Scotland's police forces. They revealed 10 to 15-year-olds were detected for 295 cases of rape or other sexual offences in the last year alone.
There were also more than 5,000 cases of assault where youngsters in this age group were detected in 2011-12, as well as almost 4,000 vandalisms and 552 cases of possession of a knife.
Over the last three years almost half the cases - 46,495 - where 10 to 15-year-olds were detected were in the Strathclyde Police area. The police force with the lowest number of offences where youngsters were detected over the period was Dumfries and Galloway, with 2,634 such cases.
Tory justice spokesman David McLetchie said: "What does it say about society that over the past three years we've had tens of thousands of children running around the country committing serious crimes and carrying weapons?" He added: "Criminal behaviour at a young age has to be nipped in the bud, otherwise it may become a lifetime of crime."
A Scottish Government spokesman said: "Recorded youth crime is falling sharply - under-18s offending has dropped by 28% since 2008-09 and offence referrals to the children's reporter have fallen for the fifth consecutive year, by 66% since 2006-07."