The aim of this study is to investigate whether there is a loss in the strength of fine- to medium-grained colloidalsilica-grouted sand after cyclic loading. First, the rheological properties of colloidal silica grouts, such as gel time and viscosity, are studied. Then, appropriate colloidal silica grouts (saline solution/colloidal silica suspension ratios of 10%, 15%, 20% and 25% by weight) are selected. The selected colloidal silica grouts are then injected into fine- to medium-grained sand specimens prepared at an overall relative density of 50%. The strength of the grouted sand specimens is determined by unconfined compression tests. The effect of curing period on the strength of the grouted samples is also investigated. After performing cyclic loading tests on grouted sand specimens at different cyclic stress ratios (0, 0.13, 0.26 0.39 and 0.52), it is observed that none of the samples failed or was damaged, and that the colloidal silica grout provides fine- to medium-grained sand with a significant resistance to cyclic deformation. The samples are then subjected to unconfined compression tests, and the results show that the loss in the strength of colloidal-silica-grouted sand is insignificant.