<p>Over the past several decades, water–fuel emulsions have been actively investigated because their use can significantly improve the performance and environmental characteristics of diesel engines. However, the stability of such emulsions, governed by phase separation of fuel and water, remains a pressing issue. Determining the water content in emulsified diesel fuel provides insight into emulsion stability. In this work, we describe a new method for determining the proton surface relaxivity at the water–fuel interface based on the kinetics of water‑drop sedimentation in the gravitational field and the transverse NMR relaxation time of ¹H nuclei in the water droplets. Unlike traditional sedimentation analysis by continuous weighing of the sediment, the proposed approach uses continuous monitoring of the NMR relaxation time T₂. It is assumed that the spin–spin relaxation time is proportional to the sediment mass. The kinetics of T₂‑time changes during sedimentation of emulsion water droplets was studied. To obtain the water‑drop size distribution, the T₂(t) data array was processed numerically. The applicability of the proposed method to highly dispersed water–fuel emulsions is limited by the very slow settling of small droplets in the gravitational field. The results obtained here can be useful for dispersion analysis of any organic emulsion containing micrometer‑sized droplets of an immiscible liquid.</p>