The aim of this paper is to study the oscillatory behavior of solutions of general third order neutral delay differential equations using a generalized Riccati transformation. We establish new sufficient conditions for oscillations of solutions. Illustrative examples are given to support our main results. The obtained results extend and improve some known criteria in the literature. There has been considerable interest in studying the oscillation of solutions of neutral delay differential equations in the last two decades. Although the oscillation of third-order equations has received less attentions relatively comparing with those of second-order, however there is an increasing interest in studying the oscillation of neutral delay third-order equations (see [2 ], [4 ], [ 6], [ 8] )