When a pulsed high-powered laser beam is focused on a target material, breakdown of the sample occurs and eventually results in the formation of a transient, and highly energetic plasma. Laser-induced breakdown spectrometry (LIBS) is a novel method of trace elemental analysis based on optical emission of laser-induced plasma. This article describes the theoretical and experimental results of the laser-induced plasma formation, recent advances in instrumentation and analytical techniques used for LIBS. The main focus is on recent developments such as portable instrumentation and novel applications such as analysis under water and in hostile environments. A brief review of some fundamental studies is also prepared and discussed.