Consider the neutral delay differential equation d/dt[y(t) + py(t − τ)] + q₁ y(t − σ₁) + q₂ y(t − σ₂) = 0, where the coefficients p, q₁, q₂ are real numbers and the delays τ, σ₁, σ₂ are nonnegative eal numbers. We prove that every solution of Eq. (1) oscillates if and only if the characteristic equation λ + λpe^−λτ + q₁e^−λσ₁ + q₂e^−λσ₂ = 0 has no real roots.