Razor-billed Curassow is widespread in Amazonia, from southeastern Colombia south to Cochabamba and Santa Cruz, Bolivia, and east across Brazil, south of the Amazon, to eastern Pará, Brazil (Hellmayr and Conover 1942, Vaurie 1967, Hilty and Brown 1986, Hennessey et al. 2003, Schulenberg et al. 2007). Razor-billed Curassow does not occur in Ecuador (Ridgely and Greenfield 2001). Although Razor-billed Curassow primarily occurs south of the Amazon, it is present north of the Amazon from extreme eastern Peru and in southeastern Colombia east to the west bank of the lower Rio Negro (Niceforo Maria and Olivares 1965, Scheuerman 1977, Borges et al. 2001).
The elevational range of Razor-billed Curassow is from the lowlands up to 1350 m (Weske 1972, Schulenberg et al. 2007), although perhaps it occurs above 900-1000 m only locally (e.g. Hennessey et al. 2003, Walker et al. 2006).