The spectrum containment of almost periodic solution of second-order neutral delay differential equations with piecewise constant of argument (EPCA, for short) of the form ( x ( t ) + p x ( t - 1 ) ) ′ ′ = q x ( 2 [ ( t + 1 ) / 2 ] ) + f ( t ) is considered. The main result obtained in this paper is different from that given by some authors for ordinary differential equations (ODE, for short) and clearly shows the differences between ODE and EPCA. Moreover, it is also different from that given for equation ( x ( t ) + p x ( t - 1 ) ) ′ ′ = q x ( [ t ] ) + f ( t ) because of the difference between [ t ] and 2 [ ( t + 1 ) / 2 ] .