In general, selenium that is determined by most spectroscopic techniques usually results in total selenium (Se). Relatively few analytical methods have been applied for the selective determination of the different selenium species present in various sample matrices. This review aims to propose the method development of Se under catalytic activation of silver nanoparticles in association with flow injection-hydride generation atomic absorption spectrometry (FI-HGAAS). In this aspect, colloidal silver is an alternative choice as the reducing agent, and of particular interest due to a lot of distinctive properties such as good conductivity, chemical stability, and catalytic and antibacterial activity. Silver nanoparticles were freshly prepared and calibrated by visible absorption spectrum. This will demonstrate the catalytic activation of Se speciation by using Ag nanoparticles in comparison with borohydride solution indicating certainly increase in its sensitivity for selenium analysis.