During World War I (1914–1918), he joined the Military Academy in Istanbul, and was appointed an officer in the Ottoman army.

Ibrahim Nassar worked as a teacher at the directorate of the Hittin school in Tiberias for five years, then in Al-Khalisa School in Safad for two years, and then in Ein Mahil in Nazareth for two years between 1922 and 1931, Where the knowledge management of the British Mandate government ended his service in the wake of his political and cultural activity and his participation in writing in the local Arab newspapers and his attempts to challenge the existing education curriculum.

In 1932 Ibrahim joined the Youth Congress Party and was responsible for the Office of the Executive Committee at the second conference in 1935.

He delivered a welcome speech to receive Prince Saud bin Abdul Aziz, while he passed through the town of Anabta on his way to Jerusalem.

During the revolt, he served as a member of the Finance Committee set up by Qawuqji, which consisted of prominent rebel leaders.