He followed a successful career as a lawyer and showed himself a capable and sensitive exponent of civil and commercial law.

After Malta was granted self-government Buhagiar was returned to the Legislative Assembly in the elections of 1921 and 1924 in the interests of the Unione Popolare Maltese (UPM). On 13 October 1922 he was appointed Minister of Justice in succession to Dr. Alfredo Caruana Gatto and exactly a year later he succeeded Senator Joseph Howard as Prime Minister.

The UPM coalition with the Labour Party came to an end on 2 January 1924 but Buhagiar led a minority government until Parliament was dissolved in APril. After the June 1924 elections, the UPM returned only 10 Members to the Legislative Assembly but Buhagiar was still asked to form a government. He led a minority government till 22 September 1924 when he resigned his seat and was appointed a judge of the Superior Courts.

A gentlemen and a democrat, Francesco Buhagiar was highly respected by all, even his political opponents. His career on the Bench was a distinguished one, earning him a reputation as an eminent practical man and an accomplished jurist.

Buhagiar continued his legal career in court till 1934 when he succumbed to complications after an attack of acute appendicitis. He died at the Blue Sisters Hospital and was buried at the Addolorata Cemetery.

Francesco Buhagiar was married to Enrichetta Said and they had five children.