Police and fire services were on the scene as emergency procedures were activated and MSPs evacuated from the building.
Business returned to normal after police gave the all-clear, the Scottish parliament said.
Tory MSPs Liz Smith, Jamie Halcro-Johnston, Edward Mountain were each sent suspect envelopes to their offices, according to the BBC.
A Scottish Parliament spokespersons tweeted: "An incident has occurred and the MSP building at Holyrood has been evacuated".More news: Disney Held Talks to Buy Most of Fox
A Conservative source told the Evening News that the packages received were invitations to the Inverness Courier newspaper's 200th anniversary celebration event.
Four packages of white powder that sparked security alert at Scottish Parliament are not being treated as suspicious, police have said.
He did not notice anything unusual, but was later told that a similar package received by Mr Halcro-Johnston had contained white powder when it was opened by a member of his staff at about 11:30.
"No other areas of the Holyrood campus are now affected and the Parliament remains open to the public at present".More news: Australia turns down NZ offer to take asylum seekers
Police officers are standing guard at the corridor that leads to MSP's offices.
"Emergency services were called at around 11.35am on Tuesday, November 7, following a report of a suspicious package having been delivered".
Scotland's parliament building was evacuated after three envelopes containing white powder were sent to lawmakers with the Conservative Tory Party.
"The public are thanked for their patience and support during this matter".More news: Lamborghini Unveils All-Electric Terzo Millennio Concept Car
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