An experimental investigation is carried out to evaluate the ultimate compressive capacity of welded stiffened aluminum panels in alloy 5083-H116 subjected to uniaxial compressive load along the short edge. A tensile test is carried out to find out the real material properties. Five full-scale stiffened panel specimens, one of them is intact and locked cracks are produced in the other four panels. A global survey of the initial geometric imperfections is performed before conducting the compressive test. Through-thickness locked cracks are located either in the center or quarter of the plate between the two attached stiffeners. The panels are tested, and their progressive collapse behavior is reported. The panels failed by two different deformation modes: stiffener tripping and local buckling of the plate. The load-shortening and load-lateral displacement relations are presented, and concluding remarks are stated regarding the effect of locked crack's location, orientation and initial imperfection on the compressive capacity of welded aluminum panels.