The effect of four coarse aggregate types on the compressive strength, flexural strength, and flexural strength/compressive strength ratio of normal- and high-strength concrete are reported. With normal-strength concrete mixtures, it was found that the coarse aggregate type did not greatly influence the mechanical properties. However, the high-strength concrete mixtures containing the limestone aggregate produced higher compressive strength than the concrete mixtures containing either gravel or granite aggregates. The flexural behavior of high-strength concrete was not affected by the aggregate type. Also, the experimental results did not show a conclusive influence of the aggregate type on the variation of flexural strength/compressive strength ratio.