A needle guard includes a clip with a canting wall to grip the needle shaft and a distal wall to block the tip thereof, wherein the canting and distal walls may be interconnected by an angled strut, a spring member, such as a leaf spring, may have a portion extending past an edge of the strut to bias the clip to grip the needle shaft, and the distal wall may be or include a stylus and have an L-shape to define a lip to help block the needle tip. The clip may have a depending heel to help pivot the clip about a ledge to grip the needle shaft. A needle support may be provided to limit flexure of the needle which might otherwise allow the needle to come loose from the clip. Arrangements for limiting rotation of the needle hub and needle guard housing are provided, as is a protective shroud to reduce the risk of inadvertent activation of the needle guard. Further, the needle guard may be used with a catheter assembly. Also provided is an improved duckbill release mechanism.