Fly ash-based geopolymers are new binding materials produced to replace the ordinary Portland cement used in concrete. In this research, the effect of alkaline activators to flyash ratio on the compressive, split tensile, flexural strength and microstructural study of fly ash-based geopolymers were studied. Alkaline activators to fly ash ratios of 0.30, 0.35, 0.40 and 0.45 and ratio of sodium silicate (Na2SiO3) to sodium hydroxide (NaOH) maintained constant throughout the study.