Though it was based on the rigid steel platform chassis of the DB6, the DBS was lower and wider than the car it replaced. However, it was actually shorter, despite a slightly longer wheelbase, due to the use of De Dion rear suspension. Styling was by the talented William Towns, whose work influenced Aston Martin for many years. A notable departure from the frontal appearance of previous models was an eye-catching fullwidth stainless steel grille incorporating quadruple quartz iodine headlamps. With individually sculptured rear seats, the DBS was marketed as a full four-seater.

The DBS was powered by the same 4-litre straight-six as the DB6, though its wide engine bay was obviously destined for a very different engine. It had been intended to be equipped from the start with a new V8 power unit, but this had suffered development problems. The delay meant that the carry-over DB6 unit had to be used on initial production cars. Inevitably, the greater frontal area and increased weight of the DBS compromised its straight-line performance, though the new rear suspension set-up gave it the upper hand on winding roads.