The accumulation of lithium by microorganisms was examined. Among the 70 strains of the 63 species tested (20 bacteria, 18 actinomycetes, 18 fungi, and 14 yeasts), a high lithium accumulating ability was exhibited by strains of the bacteria, Arthrobacter nicotianae and Brevibacterium helovolum. Lithium accumulation by A. nicotianae cells was strongly affected by the pH of the solution. The amount of accumulated lithium was maximum at pH 6. Cells immobilized with polyacrylamide gel also adsorbed lithium. They could be reused during repeated adsorptions, and adsorbed 548 μmol of lithium/g dry wt. cells. The adsorbed lithium was quantitatively and easily desorbed with 1 M hydrochloric acid using a column system.