In this review, we present and discuss a selected panel of antibody-defined markers expressed during different stages of mouse macrophage development. We distinguish four categories of markers, which are characteristic of: (1) macrophage precursors and immature macrophages (ER-MP12, ER-MP20, ER-MP54, ER-MP58); (2) mature macrophages in general (F4/80, BM8, Mac-1, Mac-2, ER-BMDM1); (3) macrophage subsets (ER-HR3, ER-MP23, ER-TR9, Forssman antigen, MOMA-1, MOMA-2, Monts-4, SER-4), and (4) IFN-gamma-stimulated macrophages (H-2Ia, LFA-1, ICAM-1, 158.2, MBR-2, TM-2, TM-4, and TM-5). It should be noted that many of the markers in this last category are inducible by other stimuli as well. The rigid classification of markers into four separate groups should be regarded as a digitalization of a continuum, thus inevitably implicating a simplification of the complex phenotypic changes that occur during mononuclear phagocyte development. Nevertheless, the current selection of antibodies against markers for different developmental stages of macrophages constitutes an important tool for characterization of mouse macrophages which participate in various biological processes.