Murine cytomegalovirus (MCMV) infection induces massive reorganization of intracellular membranes at the Early endosome/ Endosomal recycling compartment/trans-Golgi network interface (EE/ERC/TGN), thereby generating the assembly compartment (AC). The final step in virion maturation is secondary envelopment, in which the cell organelle membranes envelop cytoplasmic capsids. The identity and origin of these specialized secondary envelopment organelle(s) are unclear. The enlargement and tubulation of EE compartments within AC and retention of cargo proteins within EE-derived compartments suggest a reconfiguration of membrane flux and cargo sorting mechanisms required for efficient envelopment. In this study, we investigated the impact of EE sorting nexins (SNXs), SNX1, SNX3, SNX4, and SNX27 on MCMV infection and virion egress. SNXs are suppressed by siRNA, and the efficiency of suppression was determined by Western blot and semi-quantitative nested PCR. The effect of SNX suppression on virus entry and establishment of infection was monitored by flow cytometry using C3X-GFP MCMV and progression of infection by immunofluorescence detection of MCMV and host cell proteins. Progression of the late phase of infection was monitored with semi-quantitative analysis of viral DNA with EdU incorporation and small capsid protein (SCP) expression using S-mCherrry- SCP MCMV. Intracellular virion production and egress of infectious virions were determined by plaque assay. MCMV infection proceeded in all SNX-suppressed cells as in the control with a similar amount of assembled infectious virions in the cytosol. However, extracellular virion release was reduced by 5-10-fold after the suppression of SNX3, SNX4, and SNX27, while suppression of SNX1 had no effect. These results suggest that early endosomal SNXs play an essential role in secondary envelopment and egress of beta-herpesviruses.