A retractable syringe (30) comprising a hollow barrel (32) with a radially inwardly facing abutment surface (54) and a needle hub (40) having first engagement formation (42) integrally formed with the needle hub. A radially outer portion (50) of the first engagement formation (42) is engaged with the abutment surface (54) to radially inwardly bias the first engagement formation (42). A plunger includes a second engagement formation (60) which the first engagement formation captively engages at the end of a stroke thereby engaging the plunger (34) with the needle hub (40). The needle tip is retractable into the barrel (34) upon application of a predetermined longitudinal force to the plunger (34).
