One of the most important parameters for the design, selection, and operation of a microhydrocyclone is pressure drop. Although there are certain correlations in the literature for determining microhydrocyclone capacity curves, their applicability range is rather limited because of the narrow range of operational and geometric parameters used in the runs for their proposal. Thus, they are not suitable for predicting the experimental results obtained in this study using 42 microhydrocyclones of different size, vortex, and spigot configuration. Therefore, a new empirical correlation containing operational and geometric parameters grouped into dimensionless numbers is proposed. The selection of the dimensionless moduli and determination of the corresponding exponential coefficients have been based on stepwise multivariate nonlinear regression and optimization. The new correlation proposed provides reasonable estimations of the pressure drop for all of the experimental systems analyzed.