We have developed several new fluorescent staining procedures that enabled us to study the synthesis of cell wall material in the spherical Gram-positive bacterium Staphylococcus aureus. The results obtained support previous proposals that these cells synthesize new wall material specifically at cell division sites, in the form of a flat circular plate that is subsequently cleaved and remodelled to produce the new hemispherical poles of the daughter cells. We have shown that formation of the septal peptidoglycan is dependent on the key cell division protein FtsZ, which recruits penicillin-binding protein (PBP) 2. Unexpectedly, in FtsZ-depleted cells, the cell wall synthetic machinery becomes dispersed and new wall material is made in dispersed patches over the entire surface of the cells, which increase in volume by up to eightfold before lysing. The results have implications for understanding the nature of S. aureus morphogenesis and for inhibitors of cell division proteins as drug targets.