Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an immune-mediated progressive or relapsing demyelinating peripheral neuropathy. Other autoimmune diseases may be associated with CIDP. A 38-year-old man developed CIDP, which was subsequently associated with membranous glomerulonephritis (MGN) and tendinitis. He was treated with intravenous immunoglobulin, rituximab, and prednisone, which resulted in improvement of the clinical symptoms. This is a case report of CIDP associated with MGN and tendinitis.