In this study, two strains of cyanobacteria were able to remove mercury(II) from solution. Batch stirred experiments were conducted to determine overall capacity of each strain. Spirulina platensis and Aphanothece flocculosa gave maximum uptake values of 428 mg and 456 mg Hg2[superscript +] per gram of dry weight biomass, respectively. At a concentration of 10 ppm Hg2[superscript +], A. flocculosa was able to remove more than 98% of the mercury from solution. Both strains had an rapid initial uptake (15-30 min) with a slower second phase of adsorbtion. Each strain performed optimally at pH 6. Analysis of the uptake data was used to determine the best adsorption model for each strain. All of the mercury(II) was reclaimed from the metal laden S. platensis and A. flocculosa by treating the strains with HCI and NH4Cl respectively. The amount of mercury removed from solution was improved when co-ions Co(II), Ni(II), and Fe(III), were in solution and to a lesser degree when Zn(II) was present.