The rate of listeria abortion in Tehran was investigated. Abortion samples (200) were cold enriched at 4°C and subcultured on selective culture media containing acriflavin, nalidixic acid and potassium thiocyanate. Sera of patients were tested serologically (IF method) for screening, and results were confirmed by culturing the positive samples. Antibody against L. mOllocytogelles was obtained in 70.7% of sera but the bacteria was isolated from five samples only.