An　ultrathin　plasmonic　random　laser　is　fabricated　by　a　simple　lift　off　process,　which　consists　of　a　free-standing　polymer　membrane　embedded　with　silver　nanoparticles.　Low　threshold　random　lasing　is　observed　when　the　200-nm-thick　membrane　device　is　optically　pumped,　due　to　the　strong　plasmonic　feedback　and　high-quality　waveguide　confinement　provided　by　the　silver　nanoparticles　and　the　polymer　membrane,　respectively.　The　free-standing　polymer　membrane　is　very　flexible　and　transplantable,　which　can　be　attached　to　an　optical　fiber　end　face　to　achieve　random　lasing.　This　fabrication　technique　provides　a　promising　way　to　realize　plasmonic　random　lasing　on　surfaces　with　arbitrary　shapes.　(C)　2016　Optical　Society　of　America