NURBS have various drawbacks:

-  Extra storage is required to define traditional surfaces and curves, for instance, to represent the full circle utilizing a circumscribing square needs seven control points and 10 knots. Traditional representation needs the radius, the centre and the normal vector to plane of the circle. In 3D, this amounts to storing 38 rather than of seven numbers.

-  Inappropriate application of the weights might result in extremely bad parameterization that can demolish subsequent surface constructions.

-  Some of the interrogation techniques work better along traditional forms than with NURBS. An instance is surface/surface intersection, where this is mainly complicated to handle the "overlap" cases or "just touch".

-  Basic algorithms, such like inverse point mapping, are subject to numerical instability.

-  Before you begun feeling discouraged regarding NURBS, let us say that the above difficulty are not peculiar to NURBS. Other free-form schemes, such like those of Coons, Bezier and Gordon, exhibit the similar problems.