Mould growth is one of the major factors limiting the shelf life of bread. Olive leaves and their phenolics, which have antimicrobial and antifungal activity, have been shown to inhibit or delay the rate of a range of microorganisms, thus they might be useful as an alternative food additive. In this study, the impact of olive leaf water extract (OLWE) at different concentrations (1, 5, 10, 20 and 40%) as a natural preservative have been assayed on the prevention of fungal spoilage of wheat flour bread during the storage periods. All packaged bread samples were stored at 20±2 °C and the microbiological analyses (total viable, total yeastmould and lactic acid bacteria count) were performed. The total yeast-mould (TYM) counts of control samples increased to 5.28 log cfu/g, while those of containing 10% or higher concentrations of OLWEs were lower than 3 log cfu/g (below 1.25 log cfu/g), end of the 6 days of storage. As a result, the OLWEs positively affected the microbiological shelf life of wheat breads stored at 20 °C, when compared to the control samples.