Sixteen isolates from the vaginal discharge of women with bacterial vaginosis (non-specific vaginitis) and six provided by other investigators were divided into two groups on the basis of morphology and biochemical tests. Only one organism type was isolated from any one patient. The two groups differed in size, number of flagella, enzyme production, ability to ferment carbohydrates, hydrolyse hippurate and arginine, reduce nitrate, and produce ONPG, and in sensitivity to metronidazole. Both groups fermented glucose and maltose, produced succinate from glucose and alpha-glucosidase and leucine arylamidase.