In most tropical countries, especially in Asia, where afflicted nations included the Philippines, Thailand and Malaysia, agricultural waste was disposed of in enormous amounts. Poorly designed garbage disposal techniques are one of the biggest environmental ills. Environmental conservation efforts have been severely hampered by the disposal and management problems posed by wastes produced by industrial and agricultural operations. This study was carried out to find optimal replacement of coconut shell taken at 7, 14, and 28 days of curing by conducting mechanical properties tests. In this investigation, coconut shell concrete was produced by replacing coarse aggregate with coconut shells by 0%, 10%, 20%, and 30% of the total coarse aggregates. The results suggest that 10% replacement of coconut shell produces the optimum value for coarse aggregate replacement based on the compressive strength and Schmidt rebound hammer test results.