Amihai was born on July 11,1921 to Rachel (native of the Land of Israel and from a traditional, Zionist home) and David (born in Mogilev in what is now Belarus) Cohen in Cyprus.
In 1928, the family returned to the Land of Israel and helped in the founding of Pardes Hannah, with his father leading the settlement. On both sides, his family had deep roots as agricultural workers. Amihai studied in the local elementary school and was in the second class of the settlement’s agricultural school. He was in the Hagana until 1945, when he joined Lehi, whose mission of chasing the British occupier out of the Land of Israel and establishing a Jewish state appealed to him. In Lehi, he served in the operations division, in Pardes Hannah and in Samaria. He also disseminated promotional materials and put up posters.
He participated in an ideological course led by Gera and Eldad in Tel Aviv and one in firearms led by Hananiah in Pardes Hannah.
He served as a demolitions expert, blowing up the tracks in Pardes Hannah, as well as conducting ambushes in Ein Shemer and on the main road to Acre. He patrolled Camp 87 in Binyamina and attacking the Arabic village of Knir. In 1948, he enlisted in the IDF, serving as a demolitions officer with the rank of captain until the War of Independence ended.
In 1952, he married Haima Lezovsky. They had three children and now have numerous grandchildren.
Once he completed his military service, he returned to working in agriculture. He was strongly conscious of his national identity and active in the Tehiya Party, representing it at various conferences. He had a pleasant temperament and was a good man who always was happy to work for the common good.
He died suddenly on September 5,1991, at his home in Pardes Hannah. He was buried in the family plot in the Hadera Cemetery.