The very rare corto (short) used the bodywork developed by Francis Lombardi for the Fiat 850 "Lucciola",[2] while the largo (long) version used a floorpan lengthened by 15 cm and bodywork developed specifically by Carrocerías Costa for SEAT.

[3] At the 1971 Paris Motor Salon, the 850 Especial Lujo (Special deLuxe) was presented, only available with the 4-door largo body.

Production ended in late 1974, having been replaced by the SEAT 133, essentially an 850 rebodied in the style of the 127.

Sedans and the standard coupé received 843 cc four-cylinder engines with either 37 or 47 hp (27 or 35 kW).

The total production per year of SEAT 850 cars is shown in the following table : The SEAT 850 Sport model was based on the Fiat 850 Coupé and Spider versions and was also available in two variants: The Sport Coupé and Spider versions were also built in Spain, although they were never exported.