On the eve of the war, Egypt massed approximately 100,000 of its 160,000 troops in the Sinai, including all of its seven divisions (four infantry, two armored and one mechanized), as well as four independent infantry and four independent armored brigades. No less than a third of them were veterans of Egypt's intervention into the Yemen Civil War and another third were reservists. These forces had 950 tanks, 1,100 APCs and more than 1,000 artillery pieces. At the same time some Egyptian troops (15,000 - 20,000) were still fighting in Yemen. Nasser's ambivalence about his goals and objectives was reflected in his orders to the military. The general staff changed the operational plan four times in May 1967, each change requiring the redeployment of troops, with the inevitable toll on both men and vehicles. Towards the end of May, Nasser finally forbade the general staff from proceeding with the Qahir ("Victory") plan, which called for a light infantry screen in the forward fortifications with the bulk of the forces held back to conduct a massive counterattack against the main Israeli advance when identified, and ordered a forward defense of the Sinai. In the meantime, he continued to take actions intended to increase the level of mobilization of Egypt, Syria and Jordan, in order to bring pressure on Israel.

Syria's army had a total strength of 75,000 and amassed them along the Syrian border. Jordan's army had 55,000 troops, including 300 tanks along the Jordanian border, 250 of which were US M48 Patton, sizable amounts of M113 APCs, a new battalion of mechanized infantry, and a paratrooper battalion trained in the new US-built school. They also had 12 battalions of artillery and six batteries of 81 mm and 120 mm mortars.

Documents captured by the Israelis from various Jordanian command posts record orders from the end of May for the Hashemite Brigade to capture Ramot Burj Bir Mai'in in a night raid, codenamed "Operation Khaled". The aim was to establish a bridgehead together with positions in Latrun for an armored capture of Lod and Ramle. The "go" codeword was Sa'ek and end was Nasser. The Jordanians also planned for the capture of Motza and Sha'alvim in the strategic Jerusalem Corridor. Motza was tasked to Infantry Brigade 27 camped near Ma'ale Adummim: "The reserve brigade will commence a nighttime infiltration onto Motza, will destroy it to the foundation, and won't leave a remnant or refugee from among its 800 residents".

100 Iraqi tanks and an infantry division were readied near the Jordanian border. Two squadrons of fighter-aircraft, Hawker Hunters and MiG 21 respectively, were rebased adjacent to the Jordanian border.

On June 2, Jordan called up all reserve officers, and the West Bank commander met with community leaders in Ramallah to request assistance and cooperation for his troops during the war, assuring them that "in 3 days we'll be in Tel-Aviv".

The Arab air forces themselves were aided by volunteer pilots from the Pakistan Air Force acting in independent capacity, as well as some aircraft from Libya, Algeria, Morocco, Kuwait, and Saudi Arabia to make up for the massive losses suffered on the first day of the war.