High-performance concrete structures often exhibits early cracking due to self-desiccation, which may lead to a reduction of their service lives. Internal curing has become extensively used to mitigate the risk of early age cracking of concrete structures by reducing autogenous shrinkage. The objective of this paper was to study the effects of pre-saturated lightweight fine aggregates as internal curing agent on the autogenous shrinkage in mortar. Two main test variables were absorption ratio and replacement of lightweight fine aggregate. Three different replacement proportions (0, 10 and 20%) of normal weight fine aggregate by the lightweight fine aggregate and three different absorption ratios have been considered in the experimental work. The results show that the use of pre-saturated lightweight fine aggregate in mortar could effectively reduce autogenous shrinkage.