The goal of the operation was to halt the Allied offensives to give Japan time to prepare a new set of defenses in response to recent defeats in the Guadalcanal campaign and in New Guinea at Buna–Gona, Wau, and the Bismarck Sea.

Based on inaccurate and unintentionally exaggerated reports from the involved aircrews, Yamamoto halted the attacks on 16 April, believing the operation to be a success.

In early March 1943, the Japanese suffered heavy losses at the hands of Allied aircraft during the Battle of the Bismarck Sea.

Throughout March, Admirals Isoroku Yamamoto and Jinichi Kusaka established their headquarters in Rabaul and began planning the offensive.

After initially concentrating around Rabaul these aircraft were dispersed to several fields around Buka and Kahili on Bougainville, and at Ballale in the Shortland Islands.

[4] Allied air defenses in the area were predominately provided by U.S. fighter squadrons, reinforced by several Australian units.

[8][9] Allied reconnaissance aircraft detected increased Japanese air activity around the upper Solomons on 1 April 1943.

[10] In the days that followed the carrier-based aircraft began arriving at Rabaul from Truk in preparation to begin the air strikes of the offensive.

This was the largest raid of the operation[11] and consisted of 67 Aichi D3A2 "Val" dive bombers escorted by 110 Zeros and was met by 76 Allied fighters.

[15][16] One US Marine Corps pilot, Lieutenant James E. Swett, was later awarded the Medal of Honor after shooting down seven aircraft.

These aircraft were controlled by a radar station which attempted to guide the defending fighters into position but initially misdirected some of them to Cape Sudest.

Anti-aircraft fire from ships in the bay also contributed to the defense, and ultimately only limited damage was inflicted on one Allied merchantman.

The raid was detected by the radar station at Paga Hill 38 minutes prior to their arrival, allowing the Allies time to scramble their fighters.

Receiving advanced warning of the attack, the Australian harbor master, Commander Geoffrey Branson, ordered the vessels to disperse.

[22][15] Author Ian Shaw notes that the Milne Bay "area had a low cloud base for most of the year and the nearby mountains could make flying a dangerous proposition".

[24] The experiences of one Australian pilot during the raid highlight these dangers and were captured in an official report in the National Archives of Australia.

After recovering, he experienced engine trouble and eventually he crash landed on a reef on Sideia Island near the village of Gotai.

[21] As a result of the raid on Milne Bay, Van Heemskerk was beached after being hit by several bombs, which set it ablaze.

At the time, he believed that Allied losses were heavier than they actually were and that the operation had been successful, and the Japanese carrier-based aircraft subsequently returned to their ships.

[29] The Japanese operation did not significantly delay Allied preparations for further offensives in the South Pacific Area, although U.S. operations in the Solomons were set back about 10 days with bombing and minelaying sorties being postponed to hold back aircraft to respond if further Japanese air strikes were launched.