abstract–Three strains of oral streptococci were grown in dextrose broth, washed, and re‐suspended in saline (1.0 ml) containing 0.6 and 5.7 parts/106fluoride. The final suspensions also contained an inert dilution indicator (51Cr‐EDTA). This water‐soluble, non‐absorbable compound was added to compare its distribution with that of fluoride. The concentrations of fluoride and51Cr‐EDTA were determined in the supernatants of the bacterial suspensions. A linear relationship was noted between the volume of the bacteria and the increase in concentration of51Cr‐EDTA. The fluoride concentrations were independent of the amount of bacteria, indicating that the bacteria were permeable to fluoride. The recovery of fluoride from the supernatants and the water used for washing of the bacteria amounted to 97 ± 2%. The fluoride which was demonstrated in washed and dried bacteria seemed to be due to an incomplete washing. Neither direct nor indirect fluoride determinations indicated that fluoride was concentrated i