C.J. "Fiery" Obasi who had been visiting a friend in the slum location began to develop a story based on the unique features of the area, such as its one-exit in, one-exit out feature, as well as the fact that the area had only one source of water where everyone fetched from. Obasi felt that based on the premise which through a recent UNICEF report had placed half the population of Nigeria as not having access to clean drinking water, and listing toxic contaminations as the majority of the cause of this water population, it was feasible enough to create a story that affected the common Nigerian.
The lead character's name "Romero" played by Gabriel Afolayan is in homage to George A. Romero, one of the masters of the genre.
In an interview, Obasi said he chose the name "Ojuju" because he didn't want to use the word "zombies" in any manner or form as regards the project. He felt that if such an outbreak were to occur in the slums of Lagos, they would hardly use the word "Zombies" to describe it. Obasi felt it would be more realistic to eliminate any and all supernatural elements to the plot, and localize a well-known and celebrated pop-culture (zombie) for the Nigerian environment, rather than trying to do a Hollywood-version of what a zombie film ought to be. The entire film is in Pidgin English, Yoruba and Igbo.