I-19 attacked the SS H.M. Storey as she was bringing oil to Los Angeles on 22 December 1941, chasing the ship for an hour.

On 4 March, she arrived at the French Frigate Shoals to serve as a radio beacon for the Kawanishi H8K (Emily) flying boats that were to attack Pearl Harbor.

The remaining three torpedoes from the spread hit the U.S. battleship North Carolina and the destroyer O'Brien, the latter of which later sank on 19 October 1942 en route for repairs.

[8] From November 1942 until February 1943, I-19 assisted with nocturnal supply and reinforcement deliveries and, later, evacuations for Japanese forces on Guadalcanal.

[5] On 25 November 1943, at 20:49, 50 nautical miles (93 km) west of Makin Island, destroyer USS Radford detected I-19 on the surface with radar.