Fiber-reinforced polymer composites may offer numerous attractive features such as low cost, high specific performance and ease of production. However, there are concerns about the overall durability of these materials, especially for sustained performance under severe and changing environmental conditions. Moisture is known to have detrimental effect on the mechanical properties of composite components. However, there is a general lack of data on the effects of life-cycle thermal history on moisture absorption in fiber-reinforced polymer composites. This work investigates the effect of previous life-cycle thermal history on moisture absorption in resin transfer molded glass/epoxy composites. Disk-shaped parts (D=152.4 mm) are fabricated using EPON 815C resin and EPICURE 3282 curing agent. Reinforcement is provided by six layers of randomly oriented planar glass fiber performs with 0.459 kg/m2 surface density, yielding approximately 32 % fiber volume fraction. Samples cut from the molded disks are initially immersed in water at room temperature for 48 hours. Then, these samples are divided into three groups which are subjected to 0ºC, -25ºC or liquid nitrogen for another 48 hours, thus imparting various levels of life-cycle damage. A set of specimen undergoes the same absorption cycle at room temperature to characterize the baseline behavior of the composite samples. Afterwards, all samples undergo a desorption cycle. Specimen are subsequently immersed in water at room temperature for 18 months. Their masses are measured at periodic intervals to quantify the amount of water absorbed. Moisture intake is found to increase considerably with harsher environmental/thermal history of the different composite parts. In addition, stiffness reduction after freezing and after moisture absorption is also measured. Stiffness is found to drop for all composite parts considerably after moisture absorption. The stiffness drop is observed to be much more significant for the samples that were exposed to lower freezing temperatures before moisture absorption.