A simple numerical scheme is presented for the evaluation of fundamental and higher discrete time-eigenvalues of neutron transport equation. It is based on the direct solution of a matrix equation obtained by discretisation of integro-differential form of the transport equation by using the Sn-method with Diamond Difference scheme. The scheme is applied to mono-energetic homogeneous slab cases with isotropic scattering and verified against published accurate semi-analytical results. Although less accurate than the semi-analytical method, the scheme is more versatile. It is shown to be applicable to spatially heterogeneous cases also.