This document summarizes an experimental study on the effect of replacing granite with coconut shell as coarse aggregate in concrete. Forty-five concrete cylinders were cast with 0%, 2.5%, 5%, 7.5%, and 10% replacement to test compressive strength and workability. Testing at 7, 14, and 28 days showed that replacement lowered tensile strength but increased workability. Specifically, concrete with 2.5%, 5%, 7.5%, 10% replacement achieved 28-day tensile strengths of 1.97, 1.88, 1.81, and 1.74 MPa respectively. The results indicate coconut shell concrete is a viable construction material.