A vehicle body structure capable of reliably preventing water intrusion into an engine room is provided. For that purpose, there is provided a deck garnish (4), which is disposed so as to occlude a space between an upper surface of a lower part of a windshield (2) and a lower surface of a rear part of an engine hood (3) of a vehicle (1), and which extends in a vehicle width direction. On this front deck garnish (4), formed are: a stepped portion (42) inclined toward a front side of a vehicle body at a lower rear end of the engine hood (3); and drain grooves (43) formed at a front end of the stepped portion (42) so as to have a bag-shaped cross section and configured to communicate with a bottom portion of a deck panel (5).