At the time of the attack on Pearl Harbor, "Samidare" was assigned to Destroyer Division 2 of Destroyer Squadron 4 of the IJN 2nd Fleet together with her sister ships , , and , and had sortied from Mako Guard District as part of the "Operation M" (the invasion of the Philippines). From January 1942, "Samidare" participated in operations in the Netherlands East Indies, including the invasions of Tarakan, Balikpapan and eastern Java. During the Battle of the Java Sea, "Samidare" engaged a group of Allied destroyers and cruisers. Returning to Subic Bay in the Philippines on 16 March, "Samidare" assisted in the blockade of Manila Bay and the invasion of Cebu, returning to Yokosuka for repairs in early May. During the Battle of Midway on 4–6 June, "Samidare" was part of the Midway Occupation Force under Admiral Nobutake Kondō.