irony is a craft by which the speaker or writer, regarding the texture of the article , gives to the apparently explicit events, a thoroughly different meaning. The most important types of irony are of: word, play, situation, socratus, romance and dispense. The irony of situation is used when there is a discrepancy between the real situations and what is suitable to happen or what has been happened and what is expected to take place. Nezami, the 6th century poet, has taken advantages of irony in his poetry. When the events take the color of irony on themselves, encourage the reader to follow the story enthusiastically and at times set the smile, even sarcastically on his lips. The aim of this research is the studying of situational irony in the Khosrow and Shirin's mathnawi from Hakim Nezami Ganjawi. The outcome of this research is that in Nezami's mathnawi, after the Haft Paykar, the Khosrow and Shirin has more situational irony than the others. In other words it has more unexpected turnings in its traits.