Gyamfi had his primary school education at the Accra Royal School in James Town. As coach of the Ghana national football team, he won the African Cup of Nations three times (1963, 1965 and 1982), making him the most successful coach in the competition's history.[3] This record has since been equalled by Egypt's Hassan Shehata.[4]
Gyamfi was also the coach of the Ghana national football team during their Olympic debut at the 1964 Summer Olympics.[1] He returned to coach the Olympic team for the 1972 tournament.[1]