Water-in-diesel emulsions are known to lead to micro-explosions when exposed to high temperatures, thereby offering a technology that could improve the mixing of fuels with the ambient gas. Several factors such as the surfactant type, dispersed water droplet size, water content and coalescence rate play a key role in the onset of micro-explosion occurrence. Although these factors are likely to alter the properties of emulsion stability, however the effect of unstable emulsion on the micro-explosion occurrence is not well addressed. To address this issue, we prepared stable emulsion (SE) and unstable emulsion (UE) with 10 water content by volume and visualized during Leidenfrost effect. Our measurements indicate that the strength of micro-explosion affected by coalescence rate, which probably arises from decomposition of the emulsion. UE has a positive influence on micro-explosion occurrence, which probably again due to thermal conduction of coalesced water droplets. The study suggested that the micro-explosion caused due coalescence of a few big droplet (in case UE) rather than evaporated and cooperative of fine droplets to explode the droplet (in case SE). The temperature of micro-explosion was found to be lower in case of UE compared to SE. © 2018 Author(s).