Imbali was born in Ilondé, Portuguese Guinea in May 1956. He studied at the University of Bordeaux in France, graduating with a master's degree in political sociology and development in 1988. He subsequently worked as a researcher at the Instituto Nacional de Estudos e Pesquisa in Bissau. During the Guinea-Bissau Civil War of 1998–1999 he was an advisor to Prime Minister Francisco Fadul.