The mechanism by which herpesviruses fuse with cellular membranes to permit virus entry is still relatively poorly understood. This process is proving difficult to unravel, largely due to the fact that multiple viral envelope proteins appear to function in concert to mediate the fusion event. For Herpes Simplex Virus Type 1 (HSV1), glycoproteins B, D and the gHL heterodimer are all required for fusion, and gHL counterparts are involved in the fusion process of all other members of the herpesvirus family. An understanding of the functional domains of gH that are critical for fusion may offer the possibility of designing specific peptide inhibitors of virus entry, and recent progress has highlighted the potential usefulness of this approach. This review discusses these advances and outlines some of the similarities and differences between gH homologues of the different members of this diverse family of viruses.