Performance of notch damaged unrepaired steel I-shaped beam specimens was examined experimentally and numerically simulated using finite element modeling. Nine U-shaped notch damaged specimens and one control beam specimen were considered. The nine unrepaired laterally unsupported I-shaped full-scale steel specimens were tested in two-point loadings and the parameters considered in the study were the size and location of the notch. The notch size was 30 mm, 40 mm, and 60 mm in depth with a constant opening width of 20 mm. The location of the notch was at one-quarter, one third, and middle of the specimen clear span. All pre-damaged specimens had notches on one side of the tension flange with respect to the beam web except for two specimens where two notches were cut at the middle of the specimen clear span on both sides of the tension flange. The test specimens were modeled analytically using three-dimensional models of the bare-steel I-shaped specimens for comparison of the analytical predictions with experimental results. The test results showed the strength of the notched beams was hardly affected by the notch size or location. However, the stiffness of the beams was slightly decreased as the notch got closer to the mid-span with increased ductility. The corresponding analytical results were in good agreement with the test data.