The 340's primary selling feature was its spacious, pressurized cabin, the first in a light twin.

[1][2][3] Work on the 340 began in 1969, and the first aircraft was delivered in 1971, behind schedule because one of the prototypes crashed during flight testing in 1970.

[3] The early models have two turbocharged Continental TSIO-520-K engines with 285 hp (214 kW) each.

[1][3][4] The Cessna 335 was marketed as a low-priced, non-pressurized, version powered by 300 hp (225 kW) Continental TSIO-520-EB engines.

The prototype 335 made its maiden flight on December 5, 1978, with the first production aircraft flying in 1979.