Summary: The authors establish sufficient conditions for the oscillation of all solutions of neutral delay differential equations of even and odd order of the form \[ \frac{d^ n}{dt^ n}[y(t)+p(t)y(t-\tau)]+Q(t)y(t- C)=0,\quad t\geq t_ 0, \] where \(P,Q\in C[[t_ 0,\infty)\), R], \(\tau,\sigma \in R^+\) and \(n\geq 1\).