The Second Battle of Naktong Bulge was an engagement between United Nations ( UN ) and North Korean ( NK ) forces early in the Korean War from September 1 to September 15 , 1950 , along the Naktong River in South Korea . It was a part of the Battle of Pusan Perimeter , and was one of several large engagements fought simultaneously . The battle ended in a victory for the United Nations after large numbers of United States ( US ) and Republic of Korea ( ROK ) troops repelled a strong North Korean attack .