  C. Markett proved a Cohen type inequality for the classical Laguerre
expansions in the appropriate weighted $L^{p}$ spaces. In this paper, we get a
Cohen type inequality for the Fourier expansions in terms of discrete
Laguerre--Sobolev orthonormal polynomials with an arbitrary (finite) number of
mass points. So, we extend the result due to B. Xh. Fejzullahu and F.
Marcell\'an.
