Abstract: A biopsy needle device includes a needle assembly (30) sequentially driven by a spring loaded drive mechanism (44). The needle assembly (30) includes an outer cannula (12) through which a stylet (14) is slidably projected to cut and capture a core of the diagnostic tissue. The cannula (12) and stylet (14) slide on a pair of longitudinal rails (34, 36). A drive carriage (60) follows the path of a pair of cam guide grooves (56, 58), such that the carriage sequentially engages and displaces the cannula (12) and stylet (14), thereby producing the requisite sequential motion of the cannula (12) and stylet (14).