The naval Battle of Port Arthur thus ended inconclusively. The Russians took 150 casualties to around 90 for the Japanese. Although no ship was sunk on either side, several took damage. However, the Japanese had ship repair and drydock facilities in Sasebo with which to make repairs, whereas the Russian fleet had only very limited repair capability at Port Arthur.
It was obvious that Admiral Dewa had failed to press his reconnaissance closely enough, and that once the true situation was apparent, Admiral Togo's objection to engage the enemy under their shore batteries was justified.
The formal declaration of war between Japan and Russia was issued on 10 February 1904, a day after the battle. The attack, conducted against a largely unassuming and unprepared enemy in peacetime, has been widely compared to the Battle of Pearl Harbor.