The present paper begins with good reason to think why we use a case study approach to studying fertility and its theoretical base. We then reconnoitre ‘a theory of culture for demography’ in order to flesh out ‘a coherent method to fit cultural anthropology into the demographic enterprise: a third generation fertility study’. Such interrogation helps clarify problems and advantages in terms of theory, methodology, practicality, useful outcomes and differences. | A coherent method to fit cultural anthropology into the fertility study