New sufficient conditions for the oscillation of all solutions to a class of even-order differential equations with bounded and unbounded neutral coefficients are established, which refine, significantly simplify and generalize those in [T. Li and Y. V. Rogovchenko, Oscillation criteria for even-order neutral differential equations, Appl. Math. Lett. 61 2016, 35–41]. Examples are provided to illustrate the results and suggestions for future research are included.