Sampled-data models depend on knowledge or assumptions about the intersample behavior of the signals. In this sense, it is possible to use B-splines in the hold device as an interpolating function to represent an assumption about the smoothness of the system input signal or prior knowledge about it. In this paper, we obtain a sampled-data model for a continuous-time nonlinear system when the input is generated by a B-spline generalized hold. Moreover, an explicit characterization of the sampling zero dynamics is given, showing that these zero dynamics are asymptotically equal to the asymptotic sampling zeros of the linear case when the sampling period goes to zero.