Infrared　(IR)　nonlinear　optical　(NLO)　materials　are　the　core　devices　to　realize　IR　laser　output,　which　are　of　vital　importance　in　civilian　and　military　fields.　Non-centrosymmetric　chalcogenide　and　pnictide　compounds　have　already　been　widely　accepted　as　favorable　systems　for　IR-NLO　materials.　Compared　to　the　extensively　investigated　IR-NLO　chalcogenides　during　the　past　few　decades,　the　research　of　non-centrosymmetric　phosphides　as　IR-NLO　materials　is　relatively　scarce.　In　this　frontier　article,　the　recent　progress　of　pnictides　as　emerging　IR-NLO　candidates　has　been　highlighted　based　on　the　perspective　of　new　crystal　exploration.　These　IR-NLO　pnictides　recently　reported　were　divided　into　three　groups　from　binary　to　quaternary　according　to　their　chemical　compositions.　The　synthetic　methods,　structural　chemistry,　and　structure-activity　relationships　are　analyzed　and　summarized　in　detail.　Finally,　current　problems　and　the　future　development　of　this　field　are　also　proposed.