Iran located in arid and semiarid area of the earth with low precipitation. Iran's rainfall is mainly received in the cold period of the year. Although the total annual precipitation is low but sometime, the country receives heavy rainfall. One of the conditions that lead to heavy rainfall is cut-off low patterns. Cut-off low-pressure systems are defined as closed lows in the upper troposphere that have become completely detached from the main westerly current. The characteristics of Cut-off Lows in Iran are studied for the period of 1976–2015. To identify these systems, the Raul Nieto algorithm was used with automatic detection capabilities. The systematic identification of Cut-off Lows is realized by applying an original automated scheme using mean daily geo-potential height, wind and air temperature at 500 hPa NCEP. Cut-off Lows are more frequent during spring in the Iran, with a maximum of frequency in March. Over the period of 1976–2015, the annual Cut-off Lows frequency exhibits a weak positive trend. In this study, the most cut-off lows lasted only 2 days. Simultaneous precipitation with cut-off low pressures was compared with annual precipitation of stations. Northwest of Iran has a larger share of Cut-off low precipitation. Different Cut-off Low patterns were identified under 6 separate patterns. The highest frequency of cut-off lows are the eastern arm of omega pattern.