Intended to compete with other sport-tourers such as the Honda VFR, the ST Ducatis had a full fairing, a large dual seat and a relaxed riding position for both rider and pillion.

All five bikes in the ST series were outwardly similar, sharing the same frame, bodywork and cycle parts, but each model had a different engine, albeit that all were liquid-cooled desmodromic V-twins.

In the Ducati tradition, the frame was a tubular steel trellis item, and the conventional suspension comprised USD forks and a rear monoshock.

In 2006, the ST4s production was discontinued in favour of an ST3s variant which inherited the enhanced ST4s suspension components, but which kept the ST3 Desmotre motor unchanged.

In 2004, an upgrade to the ST line brought a modified nose fairing and dashboard, adjustable ergonomics, a trip computer, four-way (hazard) flashers, digital speedometer, a dashboard-controlled adjustable headlight, a new seat design, Euro-2 catalytic exhaust,[3] and a simplified CAN-bus wiring setup.

Dry weight was reduced by 11 kg (24 lb) due to the lighter wiring harness and simpler support structure for the nose of the bike.

The suspension in fully adjustable for the early production series, with upside-down Showa forks at the front and Sachs rear shock, the same as the Ducati 916 Superbike but with softer damper ratings.

The OE tyres are Michelin Macadam or Metzeler's MEZ4 sport radials in 120/70 ZR17 for the front and 170/60 ZR17 for the rear, on Brembo rims.

[7] The Ducati ST3 was made between 2004 and 2007 and used the DesmoTre engine, an SOHC three-valve motor which could meet anti-pollution emissions limits.

A reviewer said of the ST3: "The three-valve (two intake and one exhaust) desmotre engine has a much smoother powerband than the desmoquattro mill of the ST4 and simply runs better.