Experimental investigations on the influence of mix proportions on the strength development and behaviour of high-strength mortars have been reported. Three cement-sand (c-s) ratios of 1:2, 1:2.5 and 1:3 were adopted. At every c-s ratio, the influence of the water-cement (w-c) ratio was studied by varying the w-c ratio from 0.30 to 0.65 at a constant increment of 0.05. The compressive strengths were observed at the ages of 3, 7 and 28 days. Whereas, the tensile strength has been reported at the age of 28 days.