DNA replication, chromosome segregation and cell division are vital for the survival of all organisms. However, our knowledge regarding how these three processes are tightly coordinated to produce viable newborn cells is limited. In bacteria, the earliest stage of cell division is the formation of the cytokinetic Z ring at the division site at the cell centre (midcell). Previously we have shown that in the model Gram-positive organism, Bacillus subtilis, when the earliest stage of the initiation phase of DNA replication is inhibited, Z ring assembly at midcell is also inhibited1. It is only when DNA replication is at least 80% complete that Z rings can form at midcell. This ensures that division does not occur too early which would guillotine the partially-replicated chromosomes producing two inviable cells. This early inhibition of midcell Z rings is due, although only partly, to the inhibitory activity of the nucleoid occlusion protein, Noc, raising the question of what else is influencing Z ring assembly at this site early in the cell cycle. To further investigate how Z ring assembly is coordinated with DNA replication and chromosome segregation, we specifically examined the effect of the chromosome segregation protein, Spo0J, on midcell Z ring assembly when this early initiation phase of DNA replication is inhibited. As with Noc, in the absence of SpoOJ a significant increase in midcell Z ring assembly is observed (to ~40% of wild-type), suggesting a novel role for SpoOJ in preventing the early formation of Z rings at midcell. Interestingly, this role for Spo0J appears separate from Noc as the absence of both Noc and SpoOJ when initiation of replication is inhibited enabled wild-type levels of midcell Z rings. In others words a complete rescue of midcell Z ring assembly occurs when both Noc and SpoOJ are absent. The mechanism by which Spo0J prevents premature midcell Z ring assembly is being investigated and will be discussed, although current evidence suggests that it functions differently to that of Noc. These studies promise to shed new light on how cell-cycle events are coordinated in bacteria to ensure survival of each generation.