This chapter contains sections titled: Introduction Dendritic cell terminology and heterogeneity Antigen uptake Antigen presentation Integrated function of dendritic cells in the immune response Role for dendritic cells in allergic sensitization in humans Dendritic cells in allergic asthma Dendritic cells in atopic dermatitis Role of dendritic cells in allergic rhinitis Dendritic cells as drug targets in allergic diseases Origin and function of macrophages Homeostasis in the alveolar compartment is maintained by alveolar macrophages Function of alveolar macrophages in inflammatory conditions and asthma Conclusion References