The influence of relativistic contributions to deuteron electrodisintegration is systematically studied in various kinematic regions of energy and momentum transfer. As theoretical framework the equation-of-motion and the unitarily equivalent S-matrix approaches are used. In a (p/M )-expansion, all leading order relativistic π-exchange contributions consistent with the Bonn OBEPQ model are included. In addition, static heavy meson exchange currents including boost terms, γπρ/ω-currents, and ∆-isobar contributions are considered.Sizeable effects from the various relativistic two-body contributions, mainly from π-exchange, have been found in inclusive form factors and exclusive structure functions for a variety of kinematic regions.