Statistics taken from the Scottish Prison Service’s annual report revealed 901 men and young offenders were disciplined for taking drugs in 2014-15, compared to 790 the previous year.
The increase among female inmates was even steeper, rising 29 per cent from 79 in 2013-14 to 102 last year.
The Scottish Conservatives said more needed to be done to stop drugs finding their way into jails, pointing out prisoners have little chance of rehabilitation if illegal substances are in circulation.
The statistics also revealed increases in the number of assaults and cases where people refused to work.
However, improvements were made in the number of cases of fighting, arson and threatening behaviour.
Tory MSP Alex Johnstone said: “We know all too well that the effects of controlled drugs can be extremely dangerous to a person’s health and those around them. But the fact this is happening with such regularity in Scotland’s prisons is a cause for serious alarm.
“And the problem is getting worse, particularly among female inmates.
“Questions must be asked as to how these substances were obtained by prisoners in the first place, especially since possession is an offence in itself.”
The overall Scottish prison population is currently around 8,000, of which around 7,700 are in custody. The remainder are on Home Detention Curfews.
A spokeswoman for the Scottish Prison Service said the increase in the number of people being disciplined for drugs reflected its improved detection procedures.
She said: “A comprehensive range of security measures are in place to prevent the introduction of contraband into our prisons.
“Given the significant investment we have made in the development of new technology and staff training to detect, deter and reduce the availability and supply of illegal drugs, the increase is not unexpected.”
She added: “Recovery is the aim of all services providing treatment and rehabilitation for prisoners with drug problems and by adopting a multi-disciplinary approach with our partners.”
A Scottish Government spokeswoman said: “This is an operational matter for the Scottish Prison Service.”