He said he would not "rule out" holding on to any constituency.
The party suffered severely in the 2011 Holyrood elections, dropping from 16 MSPs to five. But Mr Rennie said there was no reason to think such a defeat would be repeated in 2015.
The LibsDems are hoping to run a series of "mini by-elections" in an attempt to strengthen the Westminster seats they hold, while targeting a handful of others.
Mr Rennnie said people living in constituencies held by the party were well aware of what the LibDems were doing for them at Westminster.
It is understood party bosses also believe their decision to enter into Coalition with the Tories and the party's subsequent U-turn on tuition fees in 2010 will be less of an issue in 2015 than it was in 2011.
Mr Rennie said: "I see no reason why we cannot win all 11 of the seats at Westminster. I would not rule any of them out."
l Tim Loughton, Tory MP for East Worthing & Shoreham, is under pressure to apologise after apparently suggesting Sarah Teather, LibDems MP for Brent Central, was a bad families minister because she does not have children. A senior Lib Dem source said: "He needs to gather whatever dignity he has left and shut up."