The goal of this study is to investigate the effect of multiple delaminations on the compressive, tensile and flexural strength of E-glass/epoxy composites and to evaluate their effects on the first critical buckling and re-buckling loads. Artificial delaminations of different sizes were inserted into four interlayers of [45(2)degrees/0(2)degrees/-45(2)degrees/90(2)degrees](s) oriented E-glass/epoxy composite using a hand lay-up method and a hot press. The effects of through-the-width strip, circular and peanut shaped delaminations and triangle and inverted triangle patterned delaminations through the thickness direction were investigated experimentally. According to the results, the presence of multiple large delaminations influences the compressive and flexural strength and critical buckling load significantly. However, tensile strength is less affected by multiple delamination. (C) 2016 Elsevier Ltd. All rights reserved.