"The five contrasting titles interrogate aspects of things that we might feel we know of Africa - violence, religion, corruption, family, community - but these are subjects that are deconstructed and beautifully remade," said the chief judge and historian Gus Casely-Hayford.
"These are challenging, arresting, provocative stories of a continent and its descendants captured at a time of burgeoning change."
The winner of the 10,000 pound ($15,200) prize will be announced in July in Oxford, England.
The four Nigerians whose 2012 titles made it to the final list are Elnathan John for his "Bayan Layi"; Tope Folarin for "Miracle"; Abubakar Adam Ibrahim for "The Whispering Trees" and Chinelo Okparanta for "America".
The Sierra Leonean entry is "Foreign Aid" by Pede Hollist.
The Caine Prize counts the African Nobel winners Wole Soyinka, Nadine Gordimer and JM Coetzee among its patrons.