This research investigated the effect of different environmental conditions including moisture, saline and alkaline conditions on the notch sensitivity of short and 2D plain woven glass fibers reinforced epoxy matrix composites fabricated by the hand lay-up technique with fiber volume content of 23.5 and 38.6 vol.%, respectively. The test was carried out through open hole tension test at constant ratio of (D/W = 0.2) and the notch sensitivity of these composites under different environments was evaluated by comparing the notched tensile strength and the characteristic distance (do) of these composites applying Whitney-Nuismer mathematical model. The results indicated that the environmental exposure has a pronounced negative effect on the notched tensile strength of all composites compared to the unconditioned state (virgin state). Moreover, the fracture zone of the composites under the alkaline environment is smooth and shows much less fiber pull out validated by SEM micrographs which distinguishes brittle failure.