Morphological features of nine wild species belonging to the genus Tephrosia PER growing in Saudi Arabia were extensively studied in order to support the diversity and simplify the identification of these species. The studied features included macro and micro morphological features of stem, leaves, flowers and pods. The most important features regarded for distinction of Saudi Arabia species of Tephrosia were pods shape, color, size, dehiscence and number of seeds per pod, inflorescences position, flower opening, shape of the upper 2 teeth of calyx, shape of sepals apex, shape of wings, length of hairs on ovary, direction of staminal tube tip, leaflets shape and surface and stem habit form and life spin. A key for the identification of the investigated species based on these morphological features is provided.