A stent deployment device (10) includes a catheter (12), a stent (14) positioned on the catheter (12), and a sleeve (16) carried on the catheter (12). The sleeve (16) has a portion (18) extending fully over and containing the stent (14). The stent deployment device (10) also includes a mechanism (20) for splitting at least the portion (18) of the sleeve (16) extending over the stent (14) and, preferably, for splitting the entire sleeve (16). Splitting of the sleeve portion (18) permits expansion of the stent (14). The mechanism (20) can include an inflatable, nondistending balloon (22) carried on the catheter (12), the stent (14) and the sleeve portion (18) being positioned over the balloon (22). The stent (14) can be self-expanding or can be expanded by the balloon (22) itself. Alternatively, the mechanism (20) can include a bulbous end (24) on the catheter (12). Longitudinal movement of the bulbous catheter end (24) with respect to the sleeve (16) splits at least the sleeve portion (18), permitting expansion of the stent (14). As further alternatives, the mechanism (20) can include a garrote (66) connected to the sleeve or a partial segment (62) of the sleeve (16) folded back alongside the stent (14). The sleeve (16) can be the same length as the catheter (12) or can be shorter than the catheter (12). In the former case, the mechanism (20) can include a pair of graspable wings (56) for splitting the full length of the sleeve (16). It is preferred that at least the portion (18) of the sleeve (16) extending over the stent (14) includes a longitudinally extending structure 46 for ensuring that the sleeve portion (18) will in fact split upon operation of the mechanism (20).