We prove sufficient conditions for the oscillation of all solutions of a scalar first-order neutral delay differential equationẋ(t)− cẋ(t − τ)+ n i=1 p i x(t − σ i ) = 0 for all 0 < c < 1, τ,σ i > 0, and p i ∈ R, i = 1, 2,...,n.2000 Mathematics Subject Classification: 34C15, 34K40.1. Introduction. The theory of neutral delay differential equations presents complications and the results which are true for neutral differential equations may not be true for nonneutral differential equations. Besides its theoretical interest, the study of oscillatory behaviour of solutions of neutral delay differential equations has some importance in applications. Neutral delay differential equations appear in networks containing lossless transmission lines (as in high-speed computers where the lossless transmission lines are used to interconnect switching circuits), in the study of vibrating masses attached to an elastic bar and also in population dynamics (see Gopalsamy In fact, Zahariev and Baȋnov [11] seems to be the first paper dealing with oscillation of neutral equations. A systematic development of oscillation theory of neutral equations was initiated by Ladas and Sficas [10].Ladas and Schultz [9] obtained a necessary and sufficient condition for oscillation of all solutions of the neutral delay differential equatioṅ