Abstract: A biopsy instrument for excising an elongated diamond-shaped tissue sample from a skin surface. The instrument has a handle with an elongated axis terminating at one end in a coaxially mounted diamond-shaped knife having a plurality of identical V-shaped cutters with downwardly sloping cutting blades. The cutters are contiguous to each other. The interior of the knife is recessed a predetermined distance inwardly of the V-shaped cutters. The inclined sharpened cutting blades cut in elongated diamond-shaped incision upon the application of axial pressure to the handle of the instrument. The remaining diamond-shaped lesions can then be easily sutured closed.