This paper reviews the current research on the speciation and determination of mercury by various analytical instruments such as, atomic absorption spectrometer (AAS), voltammeter, inductively coupled plasma optical emission spectrometer (ICP-OES), ICP-atomic emission spectrometer (AES), ICP-mass spectrometer (MS), atomic fluorescence spectrometer (AFS), spectrophotometer, spectrofluorometer, and high performance liquid chromatography (HPLC). Approximately 126 research papers on the speciation and determination of mercury by various analytical instruments published in international journals since 2015 are reviewed. All the analytical parameters, such as limit of detection, linearity range, quality assurance and quality control studies, applicability, and interfering ions studies evaluated in the reviewed articles are tabulated. This review find outs the lack of information on speciation studies of mercury in recent years. Another important prediction from this review is authors are not much studied about the concentrations of mercury in the atmosphere.