<div> Lasers have become an indispensable medical tool and new techniques and treatments involving them are being pioneered all the time. The editor and contributors begin by looking at the response of tissue to laser light. They then outline the types of lasers used in medicine, including solid-state, gas, dye and semiconductor lasers and discuss the use of lasers for diagnostics, such as optical coherence tomography, laser spectroscopy in biomedicine and optical biopsy. The final section is dedicated to applications of lasers in therapy and surgery, covering various medical fields including dermatology, urology, gynecology, ophthalmology, dentistry and neurology and concludes with a look at laser safety.</div>