Eight ultimate load tests were performed on three 36-in. deep Unsymmetrical plate girders. One girder was 25 ft long@ two were 30 ft long. All girders had the same cross section. With the area of the bottom flange 2% times larger than the top flange@ the centroidal axis was approximately one-sixth of the depth below the mid-depth of the web plate. The web slenderness ratio beta for all specimens was 295. The panels had aspect ratios alpha of 0.8@ 1.2 and 1.6. The loading conditions employed were pure bending@ dorninant shear@ and combined shear and bending. A comparison of the experimental ultimate strengths with the strengths computed using the theories developed by Basler and Thurlimann shows the girder strengths under dominant shear to be 12@ 17@ and 19 percent higher than the theoretical values. The ultimate loads from the bending tests were 6 and 9 percent higher than predicted. The tests under combined high bending and high shear gave strengths 8 percent higher and 8 and 12 percent lower than indicated by the current theoretical interaction envelope.