An international workshop on vaginal smear-based diagnosis of bacterial vaginosis was organized where 13 investigators scoring 258 slides with smears from vaginal fluid. Interobserver reproducibility of interpretations of Nugent scores, Hay/Ison scores and wet smear scores for the diagnosis of bacterial vaginosis was shown to be high. Detailed analysis of individual scoring results however indicated that basic standards of quality control to ensure robust individual readings of slides must be adhered to.