Abstract: A lancet assembly includes a reusable base unit that defines a handle for a lancet assembly and houses a biasing mechanism for driving a lancet into the finger of a user. The base unit includes a spring biased hammer that once cocked, can be released to drive a lancet. A lancet is included in a disposable end cap that may be releasible attached to one end of the base unit. The end cap includes integral resilience spring fingers that maintain the lancet completely within the end cap before and after use, and functions to return the lancet after engagement of the lancet and hammer. The end cap can be rotated to orient the end cap relative to user's finger to control the depth of penetration of the lancet into the user's finger.