The opening chapter of Nd:YAG Lasers: Technology and Applications aims at reviewing the mechanism of the use of Nd:YAG lasers in vascular lesions, specific indications for its use and treatment efficacy for these specific lesions. Recently, Nd:YAG lasers have also become popular in the treatment of non-vascular lesions. As such, the authors discuss the more recent indications of Nd:YAG lasers. Next, studies on the behavior of superduplex steel UNS S 32750 when submitted to autogenous welding with Nd:YAG pulsed laser, autogenous welding with Nd:YAG pulsed laser with subsequent refusion processes with Nd:YAG pulsed laser and hybrid welding combining Nd:YAG pulsed laser and GTAW are explored in two situations. The concluding chapter focuses on the applications of Nd:YAG lasers, including in the synthesis of nanocomposites and carbon quantum dots, generating micro- and nano-size emulsions.