In recent years, the horizontal continuous casting has been increasingly applied in a variety of aluminum products such as busbars, T-bars, foundry ingots, small diameter extrusion billets and forging feedstock, due to its high productivity and relatively low cost. By introducing the continuous process for long cast periods, feeding blockage as a unique process-related complex problem has emerged, which causes casting defects, a short cast duration and even an unexpected interruption of the cast. A literature review of the feeding blockage phenomena during continuous casting in the steel and aluminum industries is presented. The causes and mechanisms of feeding blockage in the aluminum horizontal continuous casting are proposed and discussed. Typical examples of feeding blockage from the industrial scale production with results of metallographic examination are illustrated.