Nickel and cobalt are strategically important metals. At present the higher grade nickel bearing ores and minerals are not adequately available for mineral industries for metal recovery. Hence the lower grade complex and oxidic nickel ores are the only available resource for extraction of nickel and cobalt. However recovery of metal values from lean grade complex ores through conventional metallurgical processes is becoming a challenge for mineral industries in the techno-economical point of view. Bioprocessing of complex and lean grade mineral is a new possibility to recover metal values at ambient conditions.