This paper investigates the effect of silica aerogels on mechanical (flexural and impact), non-destructive and thermal properties of glass/epoxy composites. Silica aerogels were mixed with epoxy at various volume fractions (1% and 3%) and infused with glass fabrics to produce composite laminates. Flexural tests indicated that the addition of aerogels increased the flexural strength of composites at the warp direction. Low impact energy (10-30 J) test results exhibited that impact force and energy absorption of composites were slightly increased . Higher energy (100 J) caused more severe damages and the effect of aerogels was more obvious. The thermogravimetric analysis revealed that addition of aerogels increased the thermostability. Generally, addition 1% of aerogel provides more improvement on mechanical properties and thermal stability compared to addition 3%. Although there is not a linear relationship between aerogel content and thermal conductivity, samples with 3% aerogel exhibited lower thermal conductivity values than other samples.