Abstract : This study examines the joint operation ability of the Leyte Campaign during October-December 1944. It bases the evaluation on the principles of war and how they were applied during the Leyte operations. The study addresses the various naval battles during the Leyte Gulf campaign. The Land Campaign is also examined to determine the joint operational support from the navy and the air force. The paper concludes with an evaluation of the joint problems experienced at Leyte and makes an evaluation of the coordination activities of the armed services - whether the activities of their campaigns were a joint effort or a jointless effort.