The objective of this study was to define the effects and safety margins of available Nd:YAG laser fibers with flat and conically sculpted tips for operative laparoscopy. An in vitro agar base model was designed to define the effect of the conically sculpted fiber at distances of 5 and 10 mm beyond the fiber tip, and an in vivo rat model was used to assess similar effects in the contact mode, as well as at 1, 3, 5, and 10 mm beyond the tip. The beam divergence emitted through conically sculpted tips demonstrated significant reduction in power density at 3-5 mm beyond the tip, which is suggestive of minimal risk of undesired effects. Threshold energy levels required for thermal effects are lower for darker organs than for light-colored objects. The Nd:YAG laser cutting effect is satisfactory when the conically sculpted tips are in contact with soft tissue, and subjacent organs are relatively more protected when compared to the flat tips. The potential advantages of this tool over other laser and conventional accessories for operative laparoscopy has yet to be determined.