The occurrences of Nitornus lobulatus Stål, 1859 and Nitornus parkoi (Costa Lima & Campos Seabra, 1945) from French Guiana and of N. parkoi (Hemiptera: Reduviidae: Stenopodainae) from Surinam are reported by the first time. The discovery of these species broadens their known geographic distribution. Brief comments on bionomics information and further discussion of the limited data currently available for these assassin bug species are provided.