OBJECTIVE To evaluate a systematic infectious screening program for patients who present with sudden or progressive sensorineural hearing loss (SHL) of unknown cause (negative history and clinical examination). METHOD Retrospective study of 182 patients with idiopathic SHL. One hundred six patients presented with sudden SHL, and 76 presented with progressive SHL. Serologies for herpes simplex and varicella-zoster viruses (immunoglobulin M and immunoglobulin G titers), Lyme disease (enzyme-linked immunosorbent assay), syphilis (fluorescent treponemal antibody absorption or microhemagglutination-Treponema pallidum test) and human immunodeficiency virus were performed. RESULTS The serologies were negative in 179 patients. Two patients had positive serologies for Lyme disease and another tested positive for syphilis. Both cases of suspected Lyme disease were later excluded by Western blot analysis and lumbar puncture (two false-positives). The patient with serologic syphilis was diagnosed as having latent syphilis after neurosyphilis was excluded. CONCLUSION The infection screening was positive in only 1 (0.6%) of 182 patients: the patient who was diagnosed with latent syphilis. On the basis of these results and taking into account the cost of systematic screening, we propose that serologic tests be limited to patients with suspect histories or symptomatologies, except for patients with a diagnosis of syphilis.