Ms Sturgeon said the controversial Home Office campaign was setting the "wrong tone".
It came after she wrote to the Home Office to express her concerns on behalf of a constituent after the scheme was launched at the UK Border Agency office in Brand Street, Glasgow, on July 29. The material on display invites asylum seekers and illegal immigrants to ask for help to leave, with messages such as "Is life in the UK what you expected?" and "Going home is simple."
Another shows a photo of an aircraft and says: "The plane can take you home. We can book the tickets."
In his letter replying to Ms Sturgeon, Mark Harper, minister for immigration, said: "The Home Office has 15 reporting centres across the UK. A significant proportion of those reporting to these centres have no legal right to remain in the UK, having exhausted their statutory rights of appeal. In these circumstances the Home Office has the power and duty to enforce their departure."
He said the purpose of the pilot was to allow failed asylum seekers to "return home easily and with dignity".
However, Ms Sturgeon, an MSP for Glasgow Southside, said she remained unhappy about the campaign. She said: "The branding is entirely the wrong tone for an office attended by people who may be fleeing persecution."
Her comments came as dozens gathered outside the Glasgow office yesterday to protest against the pilot.