Abstract: An oil or gas well Christmas tree guard apparatus provides an annular guard body which is protectively secured about a bolted flanged connection of the well Christmas tree, the guard so placed forming an envelope about the flanged connection and preventing access by a thief to the bolts and thus discouraging removal of the bolts from the bolted connection. The protective guard body thus prevents removal of the Christmas tree from its location at the well head by theft denying access to the bolted connection which flanges the Christmas tree to the remainder of the well. In the preferred embodiment the guard body provides a pair of annular shroud halves which are hingedly connected allowing them to be pivotally moved from an outer position allowing removal from the flanged connection to an inner closed operative position providing an overall annular guard body which is latched into position about the desired bolted connection.