Hexavalent chromium Cr (VI) is a toxic heavy metal that discharged by many industries into the water streams. It is the most poisoned form of chromium compounds that destroy the ecosystem. Microalgal species, Chlorella sp., was used as a biosorbent material to remove Cr (VI) from the Cr-contaminated effluents. Furthermore, different variables: pH, temperature, contact time, Cr (VI) concentration and algal dose were optimized in order to determine the optimum conditions that achieve the highest removal efficiency. Optimization process was achieved through two steps: one factor at a time (OFAT) experiments followed by 2⁵ general full factorial. Moreover, molecular identification was performed using 18S rRNA in order to demonstrate the species of Chlorella and it was identified as Chlorella sorokiniana. The highest chromium removal efficiency of 99.6793% was achieved at 100 ppm Cr (VI) after three days contact time. Chlorophyll ‘a’ estimation as a growth indicator stated that Chlorella sorokiniana can tolerate 100 ppm Cr (VI) for three days exposure. The results suggested that Chlorella sorokiniana is a good biosorbent material and it distinguished by its high ability to uptake Cr (VI) from solutions.