Flea-borne infections are emerging or re-emerging throughout the world, and their incidence is on the rise. Furthermore, their distribution and that of their vectors is shifting and expanding. This publication reviews general flea biology and the distribution of the flea-borne diseases of public health importance throughout the world, their principal flea vectors, and the extent of their public health burden. Such an overall review is necessary to understand the importance of this group of infections and the resources that must be allocated to their control by public health authorities to ensure their timely diagnosis and treatment.