'Immunoepidemiology' combines individual- and population-oriented approaches to create new perspectives. It examines how inter-individual differences in immune responses affect the population dynamics of micro- and macro-parasites to produce the epidemiological patterns of infection observed in heterogeneous host populations. Here, I discuss how research has only just begun to tap the potential of this integrative discipline that incorporates immunology, parasitology, genetics, epidemiology, ecology, mathematical modelling and statistics.