Laser emitted optical energy to effect wound closure and reconstruction of biological tissue. Optical energy is applied to produce thermal heating of biological tissue to a degree suitable for denaturing the tissue proteins such that the collagenous elements of the tissue form a "biological glue" to seal immediately and/or to reconstruct the tissue being heated. The collagenous glue is then reabsorbed by the body during the healing process. In a particularly advantageous method and apparatus, a Nd:YAG laser (20) tuned to 1.32 micrometers wavelength is emitted to shutter (24), lens (21), optical fiber (22), and handpiece (23) at low power levels to obtain deep tissue penetration with low thermal effect. An auxiliary laser (50) and marker laser (30) are also used with the Nd:YAG laser. The apparatus is controlled by a control unit (40) and timer (26) which is actuated by switch (25).