Do 28D
Redesigned aircraft with box fuselage, larger wing, new tail and two 380 hp (280 kW) IGSO-540 engines, seven built.

Do 28D-1
Production version of the Do 28D, with 0.5 m (1 ft 7½ in) greater wingspan and higher gross weight.
54 built.

Do 28D-2
Increased maximum takeoff weight, strengthened fuselage with enlarged cabin, 172 built.

Do 28D-2/OU
Do 28D modified as a pollution patrol aircraft
Do 28D-2T
In 1980 one German Air Force Do 28D-2 aircraft was fitted with two Avco Lycoming TIGO-540 turbocharged engines.

Do 28D-5X Turbo Skyservant
Prototype version powered by Lycoming LTP-101-600 turboprops rated at 298 kW (400 shp) each.
One built, first flying on 9 April 1978.
Also known as the TurboSky.

Do 28D-6X Turbo Skyservant
Prototype version powered by PT6A-110 turboprops, also rated at 298 kW (400 shp) each.
One built, first flying on 4 March 1980 later redesignated Dornier 128-6.

Do 28E-TNT
A Do 28D fitted with a new, high technology wing (Tragflügel Neuer Technologie – New Technology Wing) of 19.97 m (55 ft 8 in) span for trials, powered by two 533 kW (715 shp) Garrett TPE331-5-252D mounted on the wing.
One built, first flown on 14 June 1979.
Wing later used in the Dornier Do 228.

Do 28 G.92
1995 conversion of Do 28D powered by two Walter M601-D2 750 hp turboprops used for skydiving operations, seven built
Do 128-2
Improved version of Do 28D-2, replaced D-2 in 1980.

Do 128-6
Production version of the Turbo Skyservant,  six built.
Do 28D
Redesigned aircraft with box fuselage, larger wing, new tail and two 380 hp (280 kW) IGSO-540 engines, seven built.
Do 28D-1
Production version of the Do 28D, with 0.5 m (1 ft 7½ in) greater wingspan and higher gross weight. 54 built.
Do 28D-2
Increased maximum takeoff weight, strengthened fuselage with enlarged cabin, 172 built.
Do 28D-2/OU
Do 28D modified as a pollution patrol aircraft
Do 28D-2T
In 1980 one German Air Force Do 28D-2 aircraft was fitted with two Avco Lycoming TIGO-540 turbocharged engines.
Do 28D-5X Turbo Skyservant
Prototype version powered by Lycoming LTP-101-600 turboprops rated at 298 kW (400 shp) each. One built, first flying on 9 April 1978. Also known as the TurboSky.
Do 28D-6X Turbo Skyservant
Prototype version powered by PT6A-110 turboprops, also rated at 298 kW (400 shp) each. One built, first flying on 4 March 1980 later redesignated Dornier 128-6.
Do 28E-TNT
A Do 28D fitted with a new, high technology wing (Tragflügel Neuer Technologie – New Technology Wing) of 19.97 m (55 ft 8 in) span for trials, powered by two 533 kW (715 shp) Garrett TPE331-5-252D mounted on the wing. One built, first flown on 14 June 1979. Wing later used in the Dornier Do 228.
Do 28 G.92
1995 conversion of Do 28D powered by two Walter M601-D2 750 hp turboprops used for skydiving operations, seven built
Do 128-2
Improved version of Do 28D-2, replaced D-2 in 1980.
Do 128-6
Production version of the Turbo Skyservant,  six built.
Dornier Do 28