Leftowitz studied at Wellesley College before obtaining a Ph.D. in Classical Philology from Radcliffe College in 1961. During the 1980s much of her research focused on the place of women in the Classical world. She attracted broader attention for her 1996 book "Not Out of Africa", a criticism of Afrocentric claims that ancient Greek civilization derived largely from that of ancient Egypt. She argued that such claims owed more to a black nationalist political agenda than historical evidence. That decade, she also entered into a publicised argument with Africana studies scholar Tony Martin.