Environmental issues were ascended in construction field owing to the rapid growth in population, over utilization and utilization of non-renewable resources. It is necessary to look for alternatives of waste disposal and relevant constituent materials for concrete to impart sustainable development in construction industry. To effectively reduce the utilization of natural occurring fine aggregate in concrete, the biologically treated discarded foundry sand (WFS) was used as a replacement material in this investigation. Initially control concrete mix prepared with M-sand then it is replaced with untreated waste foundry sand (10%, 20%, 30%, 40% and 50%) and biologically treated used foundry sand (10%, 20%, 30%, 40% and 50%). Fresh and hardened properties were studied on all concrete mixes results were compared with conventional concrete. Test result shows that increase in strength of concrete by inclusion of Waste foundry sand (WFS) as a fractional replacement of fine aggregate.