A novel line immunoassay for the multiparametric detection of 11 antiganglioside autoantibodies (GM1, GM2, GM3, GM4, GD1a, GD1b, GD2, GD3, GT1a, GT1b, and GQ1b) was evaluated by comparing the reactivities in sera of 77 patients with suspected or definite autoimmune peripheral neuropathies (PNP), 60 blood donors, and 30 systemic lupus erythematodes (SLE) patients. At least one antiganglioside autoantibody was detectable in 97.4% of the patients with neuropathies compared to 12.2% in the control group. A broad spectrum of reactivities with more than two antiganglioside autoantibodies including all tested gangliosides except GD2 and GT1b was found in nearly one-third of the patients with neuropathies whereas in the control group autoantibody profiles with more than two reactivities were observed in two SLE patients only. For the first time anti-GM4 IgG and IgM antibodies were shown in PNP including Guillain-Barré syndrome (GBS), Miller-Fisher syndrome (MFS), and multifocal motor neuropathy (MMN). Different autoantibody profiles detectable by this multiparametric assay may help to diagnose different entities within the growing spectrum of autoimmune PNP.