Creaking sounds in the joints of the legs are commonly caused by fluid or gas accumulation in the joints. Fluid accumulation in the joints is commonly caused by acute injury resulting in intra-articular hematoma. Inflammation of the joint causes an increase in inflammatory exudate and fluid buildup in the joint, which causes the joint to creak when the joint is moved due to the presence of fluid. Gas buildup in the joint can occur as a result of open joint injury or localized gas due to a gas-producing bacterial infection, which can also cause a creaking sound when the gas is squeezed during movement. It is recommended to go to the hospital for a detailed examination and to take appropriate treatment according to the cause, which must not be ignored.